'
AUTOBIOGRAPHY
OF
SIR GEORGE BIDDELL AIRY, K.C.B.
I
SonDon: c. J. CLAY AND SONS,
CAMBRIDGE UNIVERSITY PRESS WAREHOUSE,
AVE MARIA LANE.
263, ARGYLE STREET.
: F. A. BROCKHAUS. Sorfe: THE MACMILLAN CO.
AUTOBIOGRAPHY
OF
SIR GEORGE AIRY, K.C.B,
M.A., LL.D., D.C.L., F.R.S., F.R.A.S.,
HONORARY FELLOW OF TRINITY COLLEGE, CAMBH.MHlE, ASTRONOMER ROYAL FROM' 1836 TO
EDITED BY
WILFRID AIRY, ' B.A., M.lNST.C
AT TH1
jft
';?.t reserved]
*
AUTOBIOGRAPHY
OF
SIR GEORGE BIDDELL AIRY, K.C.B.,
M.A., LL.D., D.C.L., F.R.S, F.R.A.S.,
HONORARY FELLOW OF TRINITY COLLEGE, CAMBRIDGE, ASTRONOMER ROYAL FROM 1836 TO l88l.
EDITED BY
WILFRID AIRY, B.A., M.lNST.CE,
CAMBRIDGE:
AT THE UNIVERSITY PRESS. 1896
[All Rights reserved]
Cambridge :
PRINTED BY J. AND C. F. CLAY, AT THE UNIVERSITY PRESS.
PREFACE.
THE life of Airy was essentially that of a hard-working, business man, and differed from that of other hard-working people only in the quality and variety of his work. It was not an exciting life, but it was full of interest, and his work brought him into close relations with many scientific men, and with many men high in the State. His real business life commenced after he became Astronomer Royal, and from that time forward, during the 46 years that he remained in office, he was so entirely wrapped up in the duties of his post that the history of the Observatory is the history of his life. For writing his business life there is abundant material, for he preserved all his correspondence, and the chief sources of information are as follows :
(1) His Autobiography.
(2) His Annual Reports to the Board of Visitors.
(3) His printed Papers entitled « Papers by G. B. Airy."
(4) His miscellaneous private correspondence.
(5) His letters to his wife.
(6) His business correspondence.
(i) His Autobiography, after the time that he became Astronomer Royal, is, as might be expected, mainly a record of the scientific work carried on at the Greenwich Obser- vatory : but by no means exclusively so. About the time when he took charge of the Observatory there was an immense development of astronomical enterprise : observa- tories were springing up in all directions, and the Astronomer
A B. 239026 *.
.*"'
Vi PREFACE.
Royal was expected to advise upon all of the British and Colonial Observatories. It was 'necessary also for him to keep in touch with the Continental Observatories and their work, and this he did very diligently and successfully, both by correspondence and personal intercourse with the foreign astronomers. There was also much work on important subjects more or less connected with his official duties — such as geodetical survey work, the establishment of time-balls at different places, longitude determinations, observation of eclipses, and the determination of the density of the Earth. Lastly, there was a great deal of time and work given to questions not very immediately connected with his office, but on which the Government asked his assistance in the capacity of general scientific adviser : such were the Cor- rection of the Compass in iron ships, the Railway Gauge Commission, the Commission for the Restoration of the Standards of Length and Weight, the Maine Boundary, Light- houses, the Westminster Clock, the London University, and many other questions.
Besides those above-mentioned there were a great many subjects which he took up out of sheer interest in the investigations. For it may fairly be said that every subject of a distinctly practical nature, which could be advanced by mathematical knowledge, had an interest for him : and his incessant industry enabled him to find time for many of them. Amongst such subjects were Tides and Tidal Obser- vations, Clockwork, and the Strains in Beams and Bridges. A certain portion of his time was also given to Lectures, generally on current astronomical questions, for he held it as his duty to popularize the science as far as lay in his power. And he attended the meetings of the Royal Astronomical Society with great regularity, and took a very active part in the discussions and business of the Society. He also did much work for the Royal Society, and (up to a certain date) for the British Association.
PREFACE. vii
All of the foregoing matters are recorded pretty fully in his Autobiography up to the year 1861. After that date the Autobiography is given in a much more abbreviated form, and might rather be regarded as a collection of notes for his Biography. His private history is given very fully for the first part of his life, but is very lightly touched upon during his residence at Greenwich. A great part of the Auto- biography is in a somewhat disjointed state, and appears to have been formed by extracts from a number of different sources, such as Official Journals, Official Correspondence, and Reports. In editing the Autobiography it has been thought advisable to omit a large number of short notes relating to the routine work of the Observatory, to technical and scientific correspondence, to Papers communicated to various Societies and official business connected with them, and to miscellaneous matters of minor importance. These in the aggregate occupied a great deal of time and attention. But, from their detached nature, they would have but little general interest. At various places will be found short Memoirs and other matter by the Editor.
(2) All of his Annual Reports to the Board of Visitors are attached to his Autobiography and were evidently intended to be read with it and to form part of it. These Reports are so carefully compiled and are so copious that they form a very complete history of the Greenwich Observatory and of the work carried on there during the time that he was Astronomer Royal. The first Report contained only four pages, but with the constantly increasing amount and range of work the Reports constantly increased in volume till the later Reports contained 21 pages. Extracts from these Reports relating to matters of novelty and importance, and illustrating the principles which guided him in his conduct of the Observatory, have been incorporated with the Auto- biography.
(3) The printed " Papers by G. B. Airy " are bound in
Vlll PREFACE.
14 large quarto volumes. There are 518 of these Papers, on a great variety of subjects : a list of them is appended to this history, as also is a list of the books that he wrote, and one or two of the Papers which were separately printed. They form a very important part of his life's work, and are frequently referred to in the present history. They are almost all to be found in the Transactions of Societies or in newspapers, and extend over a period of 63 years (1822 to 1885). The progress made in certain branches of science during this long period can very fairly be traced by these Papers.
(4) His private correspondence was large, and like his other papers it was carefully arranged. No business letters of any kind are included under this head. In this corre- spondence letters are occasionally found either dealing with matters of importance or in some way characteristic, and these have been inserted in this biography. As already stated the Autobiography left by Airy is confined almost entirely to science and business, and touches very lightly on private matters or correspondence.
(5) The letters to his wife are very numerous. They were written during his occasional absences from home on business or for relaxation. On these occasions he rarely let a day pass without writing to his wife, and sometimes he wrote twice on the same day. They are full of energy and interest and many extracts from them are inserted in this history. A great deal of the personal history is taken from them.
(6) All correspondence in any way connected with business during the time that he was Astronomer Royal is to be found at the Royal Observatory. It is all bound and arranged in the most perfect order, and any letter throughout this time can be found with the greatest ease. It is very bulky, and much of it is, in a historical sense, very interesting. It was no doubt mainly from this correspondence
PREFACE. IX
that the Autobiography, which so far as related to the Greenwich part of it was almost entirely a business history, was compiled.
The history of the early part of his life was written in great detail and contained a large quantity of family matter which was evidently not intended for publication. This part of the Autobiography has been compressed. The history of the latter part of his life was not written by himself at all, and has been compiled from his Journal and other sources. In both these cases, and occasionally in short paragraphs throughout the narrative, it has been found convenient to write the history in the third person.
2, THE CIRCUS,
GREENWICH.
NOTE.
The Syndics of the Cambridge University Press desire to express their thanks to Messrs Macmillan & Co. for their courteous per- mission to use in this work the steel engraving of Sir George Biddell Airy published in Nature on October 31, 1878.
'
TABLE OF CONTENTS.
CHAPTER I.
PAGES
Personal Sketch of George Biddell Airy . . . . i — 13
CHAPTER II.
From his birth to his taking his B.A. Degree at Cam- bridge . . . . . .... 14 — 48
CHAPTER III.
At Trinity College, Cambridge, from his taking his B.A. Degree to his taking charge of the Cambridge Observatory as Plumian Professor. . . . 49 — 81
CHAPTER IV.
At Cambridge Observatory, from his taking charge of the Cambridge Observatory to his residence at Greenwich Observatory as Astronomer Royal . 82 — 122
CHAPTER V. At Greenwich Observatory, 1836 — 1846 . . . 123 — 177
CHAPTER VI.
At Greenwich Observatory, 1846 — 1856 . - . . 178 — 225
CHAPTER VII. At Greenwich Observatory, 1856 — 1866 . . ; 226 — 261
CHAPTER VIII.
At Greenwich Observatory, 1866 — 1876 . . . 262 — 314
Xll TABLE OF CONTENTS.
CHAPTER IX.
PAGES
At Greenwich Observatory, from January ist, 1876, to
his resignation of office on August i5th, 1881 . 315 — 345
CHAPTER X.
At the White House, Greenwich, from his resignation of office on August i5th, 1881, to his death on January 2nd, 1892 ...... 346 — 368
APPENDIX.
List of Printed Papers by G. B. Airy, and List of Books
written by G.-B. Airy ...... 369 — 404
INDEX ... 405 — 414
CHAPTER I.
PERSONAL SKETCH OF GEORGE BIDDELL AIRY.
THE history of Airy's life, and especially the history of his life's work, is given in the chapters that follow. But it is felt that the present Memoir would be incomplete without a reference to those personal characteristics upon which the work of his life hinged and which can only be very faintly gathered from his Autobiography.
He was of medium stature and not powerfully built : as he advanced in years he stooped a good deal. His hands were large-boned and well-formed. His constitution was remarkably sound. At no period in his life does he seem to have taken the least interest in athletic sports or competitions, but he was a very active pedestrian and could endure a great deal of fatigue. He was by no means wanting in physical courage, and on various occasions, especially in boating expeditions, he ran considerable risks. In debate and controversy he had great self-reliance, and was abso- lutely fearless. His eye-sight was peculiar, and required correction by spectacles the lenses of which were ground to peculiar curves according to formulae which he himself in- vestigated : with these spectacles he saw extremely well, and he commonly carried three pairs, adapted to different distances : he took great interest in the changes that took place in his eye-sight, and wrote several Papers on the subject. In his later years he became somewhat deaf, but not to the extent of serious personal inconvenience.
A. B. i
GEORGE BIDDELL AIRY.
The ruling feature of his character was undoubtedly Order. From the time that he went up to Cambridge to the end of his life his system of order was strictly maintained. He wrote his autobiography up to date soon after he had taken his degree, and made his first will as soon as he had any money to leave. His accounts were perfectly kept by double entry throughout his life, and he valued extremely the order of book-keeping: this facility of keeping accounts was very useful to him. He seems not to have destroyed a document of any kind whatever : counterfoils of old cheque-books, notes for tradesmen, circulars, bills, and correspondence of all sorts were carefully preserved in the most complete order from the time that he went to Cambridge ; and a huge mass they formed. To a high appreciation of order he attributed in a great degree his command of mathematics, and sometimes spoke of mathematics as nothing more than a system of order carried to a considerable extent. In everything he was methodical and orderly, and he had the greatest dread of disorder creeping into the routine work of the Observatory, even in the smallest matters. As an example, he spent a whole afternoon in writing the word " Empty " on large cards, to be nailed upon a great number of empty packing boxes, because he noticed a little confusion arising from their getting mixed with other boxes containing different articles ; and an assistant could not be spared for this work without with- drawing him from his appointed duties. His arrangement of the Observatory correspondence was excellent and elaborate : probably no papers are more easy of reference than those arranged on his system. His strict habits of order made him insist very much upon detail in his business with others, and the rigid discipline arising out of his system of order made his rule irksome to such of his subordinates as did not conform readily to it : but the efficiency of the Observatory unquestionably depended mainly upon it. As his powers failed with age the ruling passion for order assumed a greater prominence; and in his last days he seemed to be more
PERSONAL SKETCH.
anxious to put letters which he received into their proper place for reference than even to master their contents.
His nature was eminently practical, and any subject which had a distinctly practical object, and could be advanced by mathematical investigation, possessed interest for him. And his dislike of mere theoretical problems and investigations was proportionately great. He was continually at war with some of the resident Cambridge mathematicians on this subject. Year after year he criticised the Senate House Papers and the Smith's Prize Papers question by question very severely : and conducted an interesting and acrimonious private correspondence with Professor Cayley on the same subject. His great mathematical powers and his command of mathematics are sufficiently evidenced by the numerous mathematical treatises of the highest order which he published, a list of which is appended to this biography. But a very important feature of his investigations was the thoroughness of them. He was never satisfied with leaving a result as a barren mathematical expression. He would reduce it, if possible, to a practical and numerical form, at any cost of labour : and would use any approximations which would conduce to this result, rather than leave the result in an un- fruitful condition. He never shirked arithmetical work : the longest and most laborious reductions had no terrors for him, and he was remarkably skilful with the various mathematical expedients for shortening and facilitating arithmetical work of a complex character. This power of handling arithmetic was of great value to him in the Observatory reductions and in the Observatory work generally. He regarded it as a duty to finish off his work, whatever it was, and the writer well remembers his comment on the mathematics of one of his old friends, to the effect that " he was too fond of leaving a result in the form of three complex equations with three unknown quantities." To one who had known, in some degree, of the enormous quantity of arithmetical work which he had turned out, and the unsparing manner in which he had devoted
I 2
GEORGE BIDDELL AIRY.
himself to it, there was something very pathetic in his discovery, towards the close of his long life, "that the figures' would not add up."
His energy and business capacity were remarkable. He was made for work and could not long be happy without it. Whatever subject he was engaged upon, he kept his object clearly in view, and made straight for it, aiming far more at clearness and directness than at elegance of periods or symmetry of arrangement. He wrote his letters with great ease and rapidity: and having written them he very rarely had occasion to re-write them, though he often added inser- tions and interlineations, even in the most important official letters. Without this it would have been impossible for him to have turned out the enormous quantity of correspondence that he did. He never dictated letters, and only availed him- self of clerical assistance in matters of the most ordinary routine. In his excursions, as in his work, he was always energetic, and could not endure inaction. Whatever there was of interest in the places that he visited he examined thoroughly and without delay, and then passed on. And he thus accomplished a great deal in a short vacation. His letters written to his wife, while he was on his excursions, are very numerous and characteristic, and afford ample proofs of his incessant energy and activity both of body and mind. They are not brilliantly written, for it was not in his nature to write for effect, and he would never give himself the trouble to study the composition of his letters, but they are straight-forward, clear, and concise, and he was never at a loss for suitable language to express his ideas. He had a wonderful capacity for enjoyment : the subjects that chiefly interested him were scenery, architecture, and antiquities, but everything novel or curious had an interest for him. He made several journeys to the Continent, but by far the greater number of his excursions were made in England and Scotland, and there were few parts of the country which he had not visited. He was very fond of the Lake District of
PERSONAL SKETCH. 5
Cumberland, and visited it very frequently, and each time that he went there the same set of views had an eternal freshness for him, and he wrote long descriptions of the scenery and effects with the same raptures as if he had seen it for the first time. Many of his letters were written from Playford, a village in a beautiful part of Suffolk, a few miles from Ipswich. Here he had a small property, and generally stayed there for a short time once or twice a year. He was extremely fond of this country, and was never tired of repeating his walks by the well-known lanes and footpaths. And, as in Cumberland, the Suffolk country had an eternal freshness and novelty for him. Wherever he went he was indefatigable in keeping up his acquaintance with his nu- merous friends and his letters abound in social reminiscences.
His memory was singularly retentive. It was much remarked at school in his early days, and in the course of his life he had stored up in his memory an incredible quantity of poetry, ballads, and miscellaneous facts and information of all sorts, which was all constantly ready and at his service. It is almost needless to add that his memory was equally accurate and extensive in matters connected with science or business.
His independence of character was no doubt due to and inseparable from his great powers. The value of his scientific work greatly depended upon his self-reliance and indepen- dence of thought. And in the heavy work of remodelling the Observatory it was a very valuable quality. This same self-reliance made him in his latter years apt to draw conclusions too confidently and hastily on subjects which he had taken up more as a pastime than as work. But whatever he touched he dealt with ably and in the most fearless truthseeking manner, and left original and vigorous opinions.
He had a remarkably well-balanced mind, and a simplicity of nature that appeared invulnerable. No amount of hero- worship seemed to have the least effect upon him. And
GEORGE BIDDELL AIRY.
from a very early time he was exposed to a great deal of it. His mind was incessantly engaged on investigations of Nature, and this seems to have been with him, as has been the case with others, a preserving influence. This simplicity of character he retained throughout his life. At the same time he was sensible and shrewd in his money matters and attentive to his personal interests. And his practical good sense in the general affairs of life, combined with his calm and steady consideration of points submitted to him, made his advice very valuable. This was especially recognized by his own and his wife's relations, who consulted him on many occasions and placed the fullest confidence in his absolute sense of justice as well as in his wise counsel. He was extremely liberal in proportion to his means, and gave away money to a large extent to all who had any claim upon him. But he was not in any sense reckless, and kept a most cautious eye on his expenses. He was not indifferent to the honours which he received in the scientific world, but he does not appear to have sought them in any way, and he certainly did not trouble himself about them.
His courtesy was unfailing : no amount of trouble could shake it. Whether it was the Secretary of the Admiralty, or a servant girl wanting her fortune told : whether a begging- letter for money, or miscellaneous invitations : all had their answer in the most clear and courteous language. But he would not grant personal interviews when he could avoid it : they took up too much of his time. His head was so clear that he never seemed to want for the clearest and most direct language in expressing his meaning, and his letters are models of terseness.
In all his views and opinions he was strongly liberal. At Cambridge at an early date he was one of the 83 members of the Senate who supported the application to permit the granting of medical degrees without requiring an expression of assent to the religious doctrines of the Church of England. And in 1868 he declined to sign a petition against the abo-
PERSONAL SKETCH.
lition of religious declarations required of persons admitted to Fellowships or proceeding to the degree of M.A. And he was opposed to every kind of narrowness and exclusiveness. When he was appointed to the post of Astronomer Royal, he stipulated that he should not be asked to vote in any political election. But all his views were in the liberal direction. He was a great reader of theology and church history, and as regarded forms of worship and the interpretation of the Scriptures, he treated them with great respect, but from the point of view of a freethinking layman. In the Preface to his " Notes on the Earlier Hebrew Scriptures " he says, "In regard to the general tone of these notes, I will first remark that I have nothing to say on the subject of verbal inspiration. With those who entertain that doctrine, I can have nothing in common. Nor do I recognize, in the pro- fessedly historical accounts, any other inspiration which can exempt them from the severest criticism that would be applicable to so-called profane accounts, written under the same general circumstances, and in the same countries." And his treatment of the subject in the " Notes " shews how entirely he took a rationalistic view of the whole question. He also strongly sided with Bishop Colenso in his fearless criticism of the Pentateuch, though he dissented from some of his conclusions. But he was deeply imbued with the spirit of religion and reflected much upon it. His whole correspond- ence conveys the impression of the most sterling integrity and high-mindedness, without a trace of affectation. In no letter does there appear a shadow of wavering on matters of principle, whether in public or private matters, and he was very clear and positive in his convictions.
The great secret of his long and successful official career was that he was a good servant and thoroughly understood his position. He never set himself in opposition to his masters, the Admiralty. He never hesitated to ask the Admiralty for what he thought right, whether in the way of money grants for various objects, or for occasional
GEORGE BIDDELL AIRY.
permission to give his services to scientific matters not immediately connected with the Observatory. Sometimes the Admiralty refused his requests, and he felt this very keenly, but he was far too busy and energetic to trouble himself about such little slights, and cheerfully accepted the situation. What was refused by one Administration was frequently granted by another; and in the meantime he was always ready to give his most zealous assistance in any matter that was officially brought before him. This cheerful readiness to help, combined with his great ability and punctuality in business matters, made him a very valuable servant, and speaking generally he had the con- fidence of the Admiralty in a remarkable degree. In many of his Reports to the Board of Visitors he speaks gratefully of the liberality of the Admiralty in forwarding scientific progress and research. In matters too which are perhaps of minor importance from the high stand-point of science, but which are invaluable in the conduct of an important business office, such for example as estimates and official correspondence, he was orderly and punctual in the highest degree. And, what is by no means unimportant, he possessed an excellent official style in correspondence, combined with great clearness of expression. His entire honesty of purpose, and the high respect in which he was held both at home and abroad, gave great weight to his recommendations.
With regard to his habits while he resided at the Observatory, his custom was to work in his official room from 9 to about 2.30, though in summer he was frequently at work before breakfast. He then took a brisk walk, and dined at about 3.30. This early hour had been prescribed and insisted upon by his physician, Dr Haviland of Cam- bridge, in whom he had great confidence. He ate heartily, though simply and moderately, and slept for about an hour after dinner. He then had tea, and from about 7 to 10 he worked in the same room with his family. He would never retire to a private room, and regarded the society of his family
PERSONAL SKETCH.
as highly beneficial in " taking the edge off his work." His powers of abstraction were remarkable : nothing seemed to disturb him ; neither music, singing, nor miscellaneous con- versation. He would then play a game or two at cards, read a few pages of a classical or historical book, and retire at ii. On Sundays he attended morning service at church, and in the evening read a few prayers very carefully and impressively to his whole household. He was very hospitable, and delighted to receive his friends in a simple ^and natural way at his house. In this he was most admirably aided by his wife, whose grace and skill made everything pleasant to their guests. But he avoided dinner-parties as much as possible — they interfered too much with his work — and with the exception of scientific and official dinners he seldom dined away from home. His tastes were entirely domestic, and he was very happy in his family. With his natural love of work, and with the incessant calls upon him, he would soon have broken down, had it not been for his system of regular relaxation. Two or three times a year he took a holiday: generally a short run of a week or ten days in the spring, a trip of a month or thereabouts in the early autumn, and about three weeks at Playford in the winter. These trips were always conducted in the most active manner, either in constant motion from place to place, or in daily active excursions. This system he maintained with great regularity, and from the exceeding interest and enjoy- ment that he took in these trips his mind was so much refreshed and steadied that he always kept himself equal to his work.
Airy seems to have had a strong bent in the direction of astronomy from his youth, and it is curious to note how well furnished he was, by the time that he became Astronomer Royal, both with astronomy in all its branches, and with the kindred sciences so necessary for the practical working and improvement of it. At the time that he went to Cambridge Physical Astronomy was greatly studied there and formed a
IO GEORGE BIDDELL AIRY.
most important part of the University course. He eagerly availed himself of this, and mastered the Physical Astronomy in the most thorough manner, as was evidenced by his Papers collected in his " Mathematical Tracts," his investigation of the Long Inequality of the Earth and Venus, and many other works. As Plumian Professor he had charge of the small Observatory at Cambridge, where he did a great deal of the observing and reduction work himself, and became thoroughly versed in the practical working of an Observatory. The result of this was immediately seen in the improved methods which he introduced at Greenwich, and which were speedily imitated at other Observatories. Optics and the Undulatory Theory of Light had been very favourite subjects with him, and he had written and lectured frequently upon them. In the construction of the new and powerful telescopes and other optical instruments required from time to time this knowledge was very essential, for in its instrumental equipment the Greenwich Observatory was entirely re- modelled during his tenure of office. And in many of the matters referred to him, as for instance that of the Light- houses, a thorough knowledge of Optics was most valuable. He had made a great study of the theory and construction of clocks, and this knowledge was invaluable to him at Greenwich in the establishment of new and more accurate astronomical clocks, and especially in the improvement of chronometers. He had carefully studied the theory of pendulums, and had learned how to use them in his ex- periments in the Cornish mines. This knowledge he after- wards utilized very effectively at the Harton Pit in comparing the density of the Earth's crust with its mean density ; and it was very useful to him in connection with geodetic surveys and experiments on which he was consulted. And his mechanical knowledge was useful in almost everything.
The subjects (outside those required for his professional work) in which he took most interest were Poetry, History, Theology, Antiquities, Architecture, and Engineering. He
PERSONAL SKETCH. II
was well acquainted with standard English poetry, and had committed large quantities to memory, which he frequently referred to as a most valuable acquisition and an ever-present relief and comfort to his mind. History and Theology he had studied as opportunity offered, and without being widely read in them he was much at home with them, and his powerful memory made the most of what he did read. An- tiquities and Architecture were very favourite subjects with him. He had visited most of the camps and castles in the United Kingdom and was never tired of tracing their con- nection with ancient military events : and he wrote several Papers on this subject, especially those relating to the Roman Invasions of Britain. Ecclesiastical Architecture he was very fond of: he had visited nearly all the cathedrals and principal churches in England, and many on the Continent, and was most enthusiastic on their different styles and merits : his letters abound in critical remarks on them. He was ex- tremely well versed in mechanics, and in the principles and theory of construction, and took the greatest interest in large engineering works. This led to much communication with Stephenson, Brunei, and other Engineers, who consulted him freely on the subject of great works on which they were engaged : in particular he rendered much assistance in con- nection with the construction of the Britannia Bridge over the Menai Straits. There were various other subjects which he read with much interest (Geology in particular), but he made no study of Natural History, and knew very little about it beyond detached facts. His industry was untiring, and in going over his books one by one it was very noticeable how large a number of them were feathered with his paper "marks," shewing how carefully he had read them and referred to them. His nature was essentially cheerful, and literature of a witty and humourous character had a great charm for him. He was very fond of music and knew a great number of songs; and he was well acquainted with the
12 GEORGE BIDDELL AIRY.
theory of music: but he was no performer. He did not sketch freehand but made excellent drawings with his Camera Lucida.
At the time when he took his degree (1823) and for many years afterwards there was very great activity of scientific investigation and astronomical enterprise in England. And, as in the times of Flamsteed and Halley, the earnest zeal of men of science occasionally led to much controversy and bitterness amongst them. Airy was by no means exempt from such controversies. He was a man of keen sensitive- ness, though it was combined with great steadiness of temper, and he never hesitated to attack theories and methods that he considered to be scientifically wrong. This led to dif- ferences with Ivory, Challis, South, Cayley, Archibald Smith, and others ; but however much he might differ from them he was always personally courteous, and the disputes generally went no farther than as regarded the special matter in question. Almost all these controversial discussions were carried on openly, and were published in the Athenaeum, the Philosophical Magazine, or elsewhere ; for he printed nearly everything that he wrote, and was very careful in the selection of the most suitable channels for publication. He regarded it as a duty to popularize as much as possible the work done at the Observatory, and to take the public into his confidence. And this he effected by articles communicated to newspapers, lectures, numerous Papers written for scientific societies, reports, debates, and critiques.
His strong constitution and his regular habits, both of work and exercise, are sufficient explanation of the good health which in general he enjoyed. Not but what he had sharp touches of illness from time to time. At one period he suffered a good deal from an attack of eczema, and at another from a varicose vein in his leg, and he was occasionally troubled with severe colds. But he bore these ailments with great patience and threw them off in course of time. He was
PERSONAL SKETCH. 13
happy in his marriage and in his family, and such troubles and distresses as were inevitable he accepted calmly and quietly. In his death, as in his life, he was fortunate : he had no long or painful illness, and he was spared the calamity of aberration of intellect, the saddest of all visitations.
CHAPTER II.
FROM HIS BIRTH TO HIS TAKING HIS B.A. DEGREE AT CAMBRIDGE.
FROM JULY 2/TH 1801 TO JANUARY ISTH 1823.
GEORGE BIDDELL AIRY was born at Alnwick in North- umberland on July 27th 1801. His father was William Airy of Luddington in Lincolnshire, the descendant of a long line of Airys who have been traced back with a very high degree of probability to a family of that name which was settled at Kentmere in Westmorland in the I4th century. A branch of this family migrated to Pontefract in Yorkshire, where they seem to have prospered for many years, but they were involved in the consequences of the Civil Wars, and one member of the family retired to Ousefleet in Yorkshire. His grandson removed to Luddington in Lincolnshire, where his descendants for several generations pursued the calling of small farmers. George Biddell Airy's mother, Ann Airy, was the daughter of George Biddell, a well-to-do farmer in Suffolk.
William Airy, the father of George Biddell Airy, was a man of great activity and strength, and of prudent and steady character. When a young man he became foreman on a farm in the neighbourhood of Luddington, and laid by his earnings in summer in order to educate himself in winter. For a person in his rank, his education was unusually good, in matters of science and in English literature. But at the age of 24 he grew tired of country labour, and obtained a post in the Excise. After serving in various Collections he was appointed Collector of the Northumberland Collection
FROM BIRTH TO B.A. DEGREE. 15
on the 1 5th August 1800, and during his service there his eldest son George Biddell Airy was born. The time over which his service as Officer and Supervisor extended was that in which smuggling rose to a very high pitch, and in which the position of Excise Officer was sometimes dangerous. He was remarkable for his activity and boldness in contests with smugglers, and made many seizures. Ann Airy, the mother of George Biddell Airy, was a woman of great natural abilities both speculative and practical, kind as a neighbour and as head of a family, and was deeply loved and respected. The family consisted of George Biddell, Elizabeth, William, and Arthur who died young.
William Airy was appointed to Hereford Collection on 22nd October 1802, and removed thither shortly after. He stayed at Hereford till he was appointed to Essex Collection on 28th February 1810, and during this time George Biddell was educated at elementary schools in writing, arithmetic, and a little Latin. He records of himself that he was not a favourite with the schoolboys, for he had very little animal vivacity and seldom joined in active play with his school- fellows. But in the proceedings of the school he was suc- cessful, and was a favourite with his master.
On the appointment of William Airy to Essex Collection, the family removed to Colchester on April 5th 1810. Here George Biddell was first sent to a large school in Sir Isaac's Walk, then kept by Mr Byatt Walker, and was soon noted for his correctness in orthography, geography, and arithmetic. He evidently made rapid progress, for on one occasion Mr Walker said openly in the schoolroom how remarkable it was that a boy 10 years old should be the first in the school. At this school he stayed till the end of 1813 and thoroughly learned arithmetic (from Walkingame's book), book-keeping by double entry (on which knowledge throughout his life he set a special value), the use of the sliding rule (which knowledge also was specially useful to him in after life), mensuration and algebra (from Bonnycastle's books). He
1 6 GEORGE BIDDELL AIRY.
also studied grammar in all its branches, and geography, and acquired some knowledge of English literature, beginning with that admirable book The Speaker, but it does not appear that Latin and Greek were attended to at this school. He records that at this time he learned an infinity of snatches of songs, small romances, &c., which his powerful memory retained most accurately throughout his life. He was no hand at active play: but was notorious for his skill in con- structing guns for shooting peas and arrows, and other mechanical contrivances. At home he relates that he picked up a wonderful quantity of learning from his father's books. He read and remembered much poetry from such standard authors as Milton, Pope, Gay, Gray, Swift, &c., which was destined to prove in after life an invaluable relaxation for his mind. But he also studied deeply an excellent Cyclopaedia called a Dictionary of Arts and Sciences in three volumes folio, and learned from it much about ship-building, naviga- tion, fortification, and many other subjects.
During this period his valuable friendship with his uncle Arthur Biddell commenced. Arthur Biddell was a prosperous farmer and valuer at Playford near Ipswich. He was a well- informed and able man, of powerful and original mind, extremely kind and good-natured, and greatly respected throughout the county. In the Autobiography of George Biddell Airy he states as follows :
" I do not remember precisely when it was that I first visited my uncle Arthur Biddell. I think it was in a winter : certainly as early as the winter of 1812 — 13. Here I found a friend whose society I could enjoy, and I entirely appreciated and enjoyed the practical, mechanical, and at the same time speculative and enquiring talents of Arthur Biddell. He had a library which, for a person in middle life, may be called excellent, and his historical and antiquarian knowledge was not small. After spending one winter holiday with him, it easily came to pass that I spent the next summer holiday with him : and at the next winter holiday, finding that there
FROM BIRTH TO B.A. DEGREE. 17
was no precise arrangement for my movements, I secretly wrote him a letter begging him to come with a gig to fetch me home with him : he complied with my request, giving no hint to my father or mother of my letter : and from that time, one-third of every year was regularly spent with him till I went to College. How great was the influence of this on my character and education I cannot tell. It was with him that I became acquainted with the Messrs Ransome, W. Cubitt the civil engineer (afterwards Sir W. Cubitt), Bernard Barton, Thomas Clarkson (the slave-trade aboli- tionist), and other persons whose acquaintance I have valued highly. It was also with him that I became acquainted with the works of the best modern poets, Scott, Byron, Campbell, Hogg, and others : as also with the Waverley Novels and other works of merit."
In 1813 William Airy lost his appointment of Collector of Excise and was in consequence very much straitened in his circumstances. But there was no relaxation in the education of his children, and at the beginning of 1814 George Biddell was sent to the endowed Grammar School at Colchester, then kept by the Rev. E. Crosse, and remained there till the summer of 1819, when he went to College. The Autobiography proceeds as follows :
" I became here a respectable scholar in Latin and Greek, to the extent of accurate translation, and composition of prose Latin : in regard to Latin verses I was I think more defective than most scholars who take the same pains, but I am not much ashamed of this, for I entirely despise the system of instruction in verse composition.
" My father on some occasion had to go to London and brought back for me a pair of 1 2-inch globes. They were invaluable to me. The first stars which I learnt from the celestial globe were a Lyrae, a Aquilae, a Cygni : and to this time I involuntarily regard these stars as the birth-stars of my astronomical knowledge. Having somewhere seen a description of a Gunter's quadrant, I perceived that I could
A. B. 2
1 8 GEORGE BIDDELL AIRY.
construct one by means of the globe : my father procured for me a board of the proper shape with paper pasted on it, and on this I traced the lines of the quadrant.
" My command of geometry was tolerably complete, and one way in which I frequently amused myself was by making paper models (most carefully drawn in outline) which were buttoned together without any cement or sewing. Thus I made models, not only of regular solids, regularly irregular solids, cones cut in all directions so as to shew the conic sections, and the like, but also of six-gun batteries, intrench- ments and fortresses of various kinds &c.
" From various books I had learnt the construction of the steam-engine : the older forms from the Dictionary of Arts and Sciences ; newer forms from modern books. The newest form however (with the sliding steam valve) I learnt from a 6-horse engine at Bawtrey's brewery (in which Mr Keeling the father of my schoolfellow had acquired a partnership). I frequently went to look at this engine, and on one occasion had the extreme felicity of examining some of its parts when it was opened for repair.
" In the mean time my education was advancing at Playford. The first record, I believe, which I have of my attention to mechanics there is the plan of a threshing- machine which I drew. But I was acquiring valuable infor- mation of all kinds from the Encyclopaedia Londinensis, a work which without being high in any respect is one of the most generally useful that I have seen. But I well remember one of the most important steps that I ever made. I had tried experiments with the object-glass of an opera-glass and was greatly astonished at the appearance of the images of objects seen through the glass under different conditions. By these things my thoughts were turned to accurate optics, and I read with care Rutherford's Lectures, which my uncle possessed. The acquisition of an accurate knowledge of the effect of optical constructions was one of the most charming attainments that I ever reached. Long before I went to
FROM BIRTH TO B.A. DEGREE. 19
College I understood the action of the lenses of a telescope better than most opticians. I also read with great zeal Nicholson's Dictionary of Chemistry, and occasionally made chemical experiments of an inexpensive kind : indeed I grew so fond of this subject that there was some thought of apprenticing me to a chemist. I also attended to surveying and made a tolerable survey and map of my uncle's farm.
" At school I was going on successfully, and distinguished myself particularly by my memory. It was the custom for each boy once a week to repeat a number of lines of Latin or Greek poetry, the number depending very much on his own choice. I determined on repeating 100 every week, and I never once fell below that number and was sometimes much above it. It was no distress to me, and great enjoyment. At Michaelmas 1816 I repeated 2394 lines, probably without missing a word. I do not think that I was a favourite with Mr Crosse, but he certainly had a high opinion of my powers and expressed this to my father. My father entertained the idea of sending me to College, which Mr Crosse recom- mended : but he heard from some college man that the expense would be £200 a year, and he laid aside all thoughts of it.
"The farm of Playford Hall was in 1813 or 1814 hired by Thomas Clarkson, the slave-trade abolitionist. My uncle transacted much business for him (as a neighbour and friend) in the management of the farm &c. for a time, and they became very intimate. My uncle begged him to examine me in Classical knowledge, and he did so, I think, twice. He also gave some better information about the probable ex- penses &c. at College. The result was a strong recommen- dation by my uncle or through my uncle that I should be sent to Cambridge, and this was adopted by my father. I think it likely that this was in 1816.
"In December 1816, Dealtry's Fluxions was bought for me, and I read it and understood it well. I borrowed Hutton's Course of Mathematics of old Mr Ransome, who had come to
2 2
2O GEORGE BIDDELL AIRY.
reside at Greenstead near Colchester, and read a good deal of it.
"About Ladyday 1817 I began to read mathematics with Mr Rogers (formerly, I think, a Fellow of Sidney College, and an indifferent mathematician of the Cambridge school), who had succeeded a Mr Tweed as assistant to Mr Crosse in the school. I went to his house twice a week, on holiday after- noons. I do not remember how long I received lessons from him, but I think to June 1818. This course was extremely valuable to me, not on account of Mr Rogers's abilities (for I understood many things better than he did) but for its train- ing me both in Cambridge subjects and in the Cambridge accurate methods of treating them. I went through Euclid (as far as usually read), Wood's Algebra, Wood's Mechanics, .Vince's Hydrostatics, Wood's Optics, Trigonometry (in a geometrical treatise and also in Woodhouse's algebraical form), Fluxions to a good extent, Newton's Principia to the end of the 9th section. This was a large quantity, but I read it accurately and understood it perfectly, and could write out any one of the propositions which I had read in the most exact form. My connexion with Mr Rogers was terminated by his giving me notice that he could not under- take to receive me any longer : in fact I was too much for him. I generally read these books in a garret in our house in George Lane, which was indefinitely appropriated to my brother and myself. I find that I copied out Vince's Conic Sections in February 1819. The first book that I copied was the small geometrical treatise on Trigonometry, in May 1817: to this I was urged by old Mr Ransome, upon my complaining that I could not purchase the book : and it was no bad lesson of independence to me."
During the same period 1817 — 1819 he was occupied at school on translations into blank verse from the ^neid and Iliad, and read through the whole of Sophocles very carefully.
The Classical knowledge which he thus gained at school
FROM BIRTH TO B.A. DEGREE. 21
and subsequently at Cambridge was sound, and he took great pleasure in it : throughout his life he made a practice of keeping one or other of the Classical Authors at hand for occasional relaxation. He terminated his schooling in June 1819. Shortly afterwards his father left Colchester and went to reside at Bury St Edmund's. The Autobiography pro- ceeds as follows :
" Mr Clarkson was at one time inclined to recommend me to go to St Peter's College (which had been much enriched by a bequest from a Mr Gisborne). But on giving some account of me to his friend Mr James D. Hustler, tutor of Trinity College, Mr Hustler urged upon him that I was exactly the proper sort of person to go to Trinity College. And thus it was settled (mainly by Mr Clarkson) that I should be entered at Trinity College. I think that I was sent for purposely from Colchester to Playford, and on March 6th, 1819, I rode in company with Mr Clarkson from Playford to Sproughton near Ipswich to be examined by the Rev. Mr Rogers, incumbent of Sproughton, an old M.A. of Trinity College : and was examined, and my certificate duly sent to Mr Hustler : and I was entered on Mr Hustler's side as Sizar of Trinity College.
"In the summer of 1819 I spent some time at Playford. On July 27th, 1819 (my birthday, 18 years old), Mr Clarkson invited me to dinner, to meet Mr Charles Musgrave, Fellow of Trinity College, who was residing for a short time at Grundisburgh, taking the church duty there for Dr Ramsden, the Rector. It was arranged that I should go to Grun- disburgh the next day (I think) to be examined in mathe- matics by Mr Musgrave. I went accordingly, and Mr Musgrave set before me a paper of questions in geometry, algebra, mechanics, optics, &c. ending with the first proposi- tion of the Principia. I knew nothing more about my answers at the time : but I found long after that they excited so much admiration that they were transmitted to Cam- bridge (I forget whether to Mr Musgrave's brother, a Fellow
22 GEORGE BIDDELL AIRY.
of Trinity College and afterwards Archbishop of York, or to Mr Peacock, afterwards Dean of Ely) and were long preserved.
" The list of the Classical subjects for ,the first year in Trinity College was transmitted to me, as usual, by Mr Hustler. They were — The Hippolytus of Euripides, the 3rd Book of Thucydides, and the 2nd Philippic of Cicero. These I read carefully and noted before going up. Mr Hustler's family lived in Bury; and I called on him and saw him in October, introduced by Mr Clarkson. On the morning of October i8th, 1819, 1 went on the top of the coach to Cambridge, knowing nobody there but Mr Hustler, but having letters of introduction from Mr Charles Musgrave to Professor Sedgwick, Mr Thomas Musgrave, and Mr George Peacock, all Fellows of Trinity College.
" I was set down at the Hoop, saw Trinity College for the first time, found Mr Hustler, was conducted by his servant to the robe-maker's, where I was invested in the cap and blue gown, and after some further waiting was installed into lodgings in Bridge Street. At 4 o'clock I went to the College Hall and was introduced by Mr Hustler to several undergraduates, generally clever men, and in the evening I attended Chapel in my surplice (it being St Luke's day) and witnessed that splendid service of which the occasional exhibition well befits the place.
" As soon as possible, I called on Mr Peacock, Mr Mus- grave, and Professor Sedgwick. By all I was received with great kindness: my examination papers had been sent to them, and a considerable reputation preceded me. Mr Peacock at once desired that I would not consider Mr C. Musgrave's letter as an ordinary introduction, but that I would refer to him on all occasions. And I did so for several years, and always received from him the greatest assistance that he could give. I think that I did not become acquainted with Mr Whewell till the next term, when I met him at a break- fast party at Mr Peacock's. Mr Peacock at once warned me
FROM BIRTH TO B.A. DEGREE. 23
to arrange for taking regular exercise, and prescribed a walk of two hours every day before dinner : a rule to which I attended regularly, and to which I ascribe the continuance of good general health.
"I shewed Mr Peacock a manuscript book which contained a number of original Propositions which I had investigated. These much increased my reputation (I really had sense enough to set no particular value on it) and I was soon known by sight to almost everybody in the University. A ridiculous little circumstance aided in this. The former rule of the University (strictly enforced) had been that all students should wear drab knee-breeches : and I, at Mr Clarkson's recommendation, was so fitted up. The struggle between the old dress and the trowsers customary in society was still going on but almost terminated, and I was one of the very few freshmen who retained the old habiliments. This made me in some measure distinguishable : however at the end of my first three terms I laid these aside.
" The College Lectures began on Oct. 22 : Mr Evans at 9 on the Hippolytus, and Mr Peacock at 10 on Euclid (these being the Assistant Tutors on Mr Hustler's side) : and then I felt myself established.
" I wrote in a day or two to my uncle Arthur Biddell, and I received from him a letter of the utmost kindness. He entered gravely on the consideration of my prospects, my wants, &c. : and offered at all times to furnish me with money, which he thought my father's parsimonious habits might make him unwilling to do. I never had occasion to avail myself of this offer: but it was made in a way which in no small degree strengthened the kindly feelings that had long existed between us.
"I carefully attended the lectures, taking notes as appeared necessary. In Mathematics there were geometrical problems, algebra, trigonometry (which latter subjects the lectures did not reach till the terms of 1820). Mr Peacock gave me a copy of Lacroix's Differential Calculus as translated by himself
24 GEORGE BIDDELL AIRY.
and Herschel arid Babbage, and also a copy of their Ex- amples. At this time, the usfe of Differential Calculus was just prevailing over that of Fluxions (which I had learnt). I betook myself to it with great industry. I also made myself master of the theories of rectangular coordinates and some of the differential processes applying to them, which only a few of the best of the university mathematicians then wholly possessed. In Classical subjects I read the Latin (Seneca's) and English Hippolytus, Racine's Phedre (which my sister translated for me), and all other books to which I was referred, Aristotle, Longinus, Horace, Bentley, Dawes &c., made verse translations of the Greek Hippolytus, and was constantly on the watch to read what might be advan- tageous.
" Early in December Mr Hustler sent for me to say that one of the Company of Fishmongers, Mr R. Sharp, had given to Mr John H. Smyth, M.P. for Norwich, the presentation to a small exhibition of £20 a year, which Mr Smyth had placed in Mr Hustler's hands, and which Mr Hustler immediately conferred on me. This was my first step towards pecuniary independence. I retained this exhibition till I became a Fellow of the College.
"I stayed at Cambridge during part of the winter vacation, and to avoid expense I quitted my lodgings and went for a time into somebody's rooms in the Bishop's Hostel. (It is customary for the tutors to place students in rooms when their right owners are absent.) I took with me Thucydides and all relating to it, and read the book, upon which the next term's lectures were to be founded, very carefully. The latter part of the vacation I spent at Bury, where I began with the assistance of my sister to pick up a little French : as I per- ceived that it was absolutely necessary for enabling me to read modern mathematics.
" During a part of the time I employed myself in writing out a paper on the geometrical interpretation of the alge- braical expression V— i. I think that the original suggestion
FROM BIRTH TO B.A. DEGREE. 2$
of perpendicular line came from some book (I do not re- member clearly), and I worked it out in several instances pretty well, especially in De Moivre's Theorem. I had spoken of it in the preceding term to Mr Peacock and he encouraged me to work it out. The date at the end is 1820, January 21. When some time afterwards I spoke of it to Mr Hustler, he disapproved of my employing my time on such speculations. About the last day of January I returned to Cambridge, taking up my abode in my former lodgings. I shewed my paper on V— I to Mr Peacock, who was much pleased with it and shewed it to Mr Whewell and others.
" On February I I commenced two excellent customs. The first was that I always had upon my table a quire of large-sized scribbling-paper sewn together : and upon this paper everything was entered : translations into Latin and out of Greek, mathematical problems, memoranda of every kind (the latter transferred when necessary to the subsequent pages), and generally with the date of the day. This is a most valuable custom. The other was this : as I perceived that to write Latin prose well would be useful to me, I wrote a translation of English into Latin every day. However much pressed I might be with other business, I endeavoured to write at least three or four words, but if possible I wrote a good many sentences.
" I may fix upon this as the time when my daily habits were settled in the form in which they continued for several years. I rose in time for the chapel service at 7. It was the College regulation that every student should attend Chapel four mornings and four evenings (Sunday being one of each) in every week : and in this I never failed. After chapel service I came to my lodgings and breakfasted. At 9 I went to College lectures, which lasted to n. Most of my con- temporaries, being intended for the Church, attended also divinity lectures : but I never did. I then returned, put my lecture notes in order, wrote my piece of Latin prose, and then employed myself on the subject which I was reading for
26 GEORGE BIDDELL AIRY.
the time : usually taking mathematics at this hour. At 2 or a little sooner I went out for a long walk, usually 4 or 5 miles into the country: sometimes if I found companions I rowed on the Cam (a practice acquired rather later). A little before 4 I returned, and at 4 went to College Hall. After dinner I lounged till evening chapel time, ^ past 5, and returning about 6 I then had tea. Then I read quietly, usually a classical subject, till 1 1 ; and I never, even in the times when I might seem most severely pressed, sat up later. " From this time to the close of the annual examination (beginning of June) I remained at Cambridge, stopping there through the Easter Vacation. The subjects of the mathe- matical lectures were ordinary algebra and trigonometry : but Mr Peacock always had some private problems of a higher class for me, and saw me I believe every day. The subjects of the Classical lectures were, the termination of Hippolytus, the book of Thucydides and the oration of Cicero. In mathematics I read Whewell's Mechanics, then just published (the first innovation made in the Cambridge system of Physical Sciences for many years) : and I find in my scrib- bling-paper notes, integrals, central forces, Finite Differences, steam-engine constructions and powers, plans of bridges, spherical trigonometry, optical calculations relating to the achromatism of eye-pieces and achromatic object-glasses with lenses separated, mechanical problems, Transit of Venus, various problems in geometrical astronomy (I think it was at this time that Mr Peacock had given me a copy of Wood- house's Astronomy 1st Edition), the rainbow, plans for anemo- meter and for a wind-pumping machine, clearing lunars, &c., with a great number of geometrical problems. I remark that my ideas on the Differential Calculus had not acquired on some important points the severe accuracy which they acquired in a few months. In Classics I read the Persae of ^Eschylus, Greek and Roman history very much (Mitford, Hooke, Ferguson) and the books of Thucydides introductory to that of the lecture subject (the 3rd): and attended to Chronology.
FROM BIRTH TO B.A. DEGREE. 27
On the scribbling-paper are verse-translations from Euripides, careful prose-translations from Thucydides, maps, notes on points of grammar &c. I have also little MS. books with abundant notes on all these subjects: I usually made a little book when I pursued any subject in a regular way.
" On May 1st Mr Dobree, the head lecturer, sent for me to say that he appointed me head-lecturer's Sizar for the next year. The stipend of this office was £10, a sum upon which I set considerable value in my anxiety for pecuniary inde- pendence: but it was also gratifying to me as shewing the way in which I was regarded by the College authorities.
"On Wednesday, May 24th, 1820, the examination began. I was anxious about the result of the examination, but only in such a degree as to make my conduct perfectly steady and calm, and to prevent me from attempting any extraordinary exertion.
" When the Classes were published the first Class of the Freshman's Year (alphabetically arranged, as is the custom) stood thus: Airy, Boileau, Childers, Drinkwater, Field, Iliff, Malkin, Myers, Romilly, Strutt, Tate, Winning. It was soon known however that I was first of the Class. It was generally expected (and certainly by me) that, considering how great a' preponderance the Classics were understood, in the known system of the College, to have in determining the order of merit, Field would be first. However the number of marks which Field obtained was about 1700, and that which I obtained about 1900. No other competitor, I believe, was near us." — In a letter to Airy from his College Tutor, Mr J. D. Hustler, there is the following passage : " It is a matter of extreme satisfaction to me that in the late exami- nation you stood not only in the First Class but first of the first. I trust that your future exertions and success will be commensurate with this honourable beginning."
" Of the men whom I have named, Drinkwater (Bethune) was afterwards Legal Member of the Supreme Court of India, Field was afterwards Rector of Reepham, Romilly
28 GEORGE BIDDELL AIRY.
(afterwards Lord Rorpilly) became Solicitor-General, Strutt (afterwards Lord Belper) became M.P. for Derby and First Commissioner of Railways, Tate was afterwards master of Richmond Endowed School, Childers was the father of Childers who was subsequently First Lord of the Admiralty.
" I returned to Bury immediately. While there, some students (some of them men about to take their B.A. degree at the next January) applied to me to take them as pupils, but I declined. This year of my life enabled me to under- stand how I stood among men. I returned to Cambridge about July nth. As a general rule, undergraduates are not allowed to reside in the University during the Long Vacation. I believe that before I left, after the examination, I had made out that I should be permitted to reside: or I wrote to Mr Hustler. I applied to Mr Hustler to be lodged in rooms in College : and was put, first into rooms in Bishop's Hostel, and subsequently into rooms in the Great Court.
"The first affair that I had in College was one of disap- pointment by no means deserving the importance which it assumed in my thoughts. I had been entered a Sizar, but as the list of Foundation Sizars was full, my dinners in Hall were paid for. Some vacancies had arisen : and as these were to be filled up in order of merit, I expected one : and in my desire for pecuniary independence I wished for it very earnestly. However, as in theory all of the first class were equal, and as there were some Sizars in it senior in entrance to me, they obtained places first : and I was not actually appointed till after the next scholarship examination (Easter 1821). However a special arrangement was made, allowing me (I forget whether others) to sit at the Foundation-Sizars' table whenever any of the number was absent : and in conse- quence I received practically nearly the full benefits.
" Mr Peacock, who was going out for the Vacation, allowed me access to his books. I had also (by the assistance of various Fellows, who all treated me with great kindness, almost to a degree of respect) command of the University
FROM BIRTH TO B.A. DEGREE. 29
Library and Trinity Library : and spent this Long Vacation, like several others, very happily indeed.
"The only non-mathematical subjects of the next exami- nation were The Gospel of St Luke3 Paley's Evidences, and Paley's Moral and Political Philosophy. Thus my time was left more free to mathematics and to general classics than last year. I now began a custom which I maintained for some years. Generally I read mathematics in the morning, and classics for lectures in the afternoon : but invariably I began at to o'clock in the evening to read with the utmost severity some standard classics (unconnected with the lec- tures) and at 1 1 precisely I left off and went to bed. I con- tinued my daily translations into Latin prose as before.
"On August 24th, 1820, Rosser, a man of my own year, engaged me as private tutor, paying at the usual rate (£14 for a part of the Vacation, and £14 for a term): and immedi- ately afterwards his friend Bedingfield did the same. This occupied two hours every day, and I felt that I was now com- pletely earning my own living. I never received a penny from my friends after this time.
" I find on my scribbling-paper various words which shew that in reading Poisson I was struggling with French words. There are also Finite Differences and their Calculus, Figure of the Earth (force to the center), various Attractions (some evidently referring to Maclaurin's), Integrals, Conic Sections, Kepler's Problem, Analytical Geometry, D'Alembert's Theorem, Spherical Aberration, Rotations round three axes (apparently I had been reading Euler), Floating bodies, Evolute of Ellipse, Newton's treatment of the Moon's Varia- tion. I attempted to extract something from Vince's Astro- nomy on the physical explanation of Precession : but in despair of understanding it, and having made out an expla- nation for myself by the motion round three axes, I put together a little treatise (Sept. 10, 1820) which with some corrections and additions was afterwards printed in my Mathematical Tracts. On Sept. I4th I bought Woodhouse's
30 GEORGE BIDDELL AIRY.
Physical Astronomy, .and this, was quite an epoch in my mathematical knowledge. First, I was compelled by the process of " changing the independent variable " to examine severely the logic of the Differential Calculus. Secondly, I was now able to enter on the Theory of Perturbations, which for several years had been the desired land to me.
"At the Fellowship Election of Oct. ist, Sydney Walker (among other persons) was elected Fellow. He then quitted the rooms in which he had lived (almost the worst in the College), and I immediately took them. They suited me well and I lived very happily in them till I was elected Scholar. They are small rooms above the middle staircase on the south side of Neville's Court. (Mr Peacock's rooms were on the same staircase.) I had access to the leads on the roof of the building from one of my windows. This was before the New Court was built : my best window looked upon the garden of the College butler.
" I had brought to Cambridge the telescope which I had made at Colchester, and about this time I had a stand made by a carpenter at Cambridge : and I find repeated observa- tions of Jupiter and Saturn made in this October term.
"Other mathematical subjects on my scribbling-paper are: Geometrical Astronomy, Barometers (for elevations), Mac- laurin's Figure of the Earth, Lagrange's Theorem, Integrals, Differential Equations of the second order, Particular Solu- tions. In general mathematics I had much discussion with Atkinson (who was Senior Wrangler, January 1821), and in Physics with Rosser, who was a friend of Sir Richard Phillips, a vain objector to gravitation. In Classics I read ^Eschylus and Herodotus.
"On October 5th I received notice from the Head Lecturer to declaim in English with Winning. (This exercise consists in preparing a controversial essay, learning it by heart, and speaking it in Chapel after the Thursday evening's service.) On October 6th we agreed on the subject, " Is natural differ- ence to be ascribed to moral or to physical causes ? " I taking
FROM BIRTH TO B.A. DEGREE. 31
the latter side. I spoke the declamation (reciting it without missing a word) on October 25th. On October 26th I received notice of Latin declamation with Myers : subject agreed on, " Utrum civitati plus utilitatis an incommodi affe- rant leges quae ad vitas privatorum hominum ordinandas pertinent " ; I took the former. The declamation was recited on November II, when a curious circumstance occurred. My declamation was rather long : it was the first Saturday of the term on which a declamation had been spoken : and it was the day on which arrived the news of the withdrawal of the Bill of Pains and Penalties against Queen Caroline. (This trial had been going on through the summer, but I knew little about it.) In consequence the impatience of the undergraduates was very great, and there was such an uproar of coughing &c. in the Chapel as probably was never known. The Master (Dr Wordsworth, appointed in the beginning of the summer on the death of Dr Mansell, and to whom I had been indirectly introduced by Mrs Clarkson) and Tutors and Deans tried in vain to stop the hubbub. However I went on steadily to the end, not at all frightened. On the Monday the Master sent for me to make a sort of apology in the name of the authorities, and letters to the Tutors were read at the Lectures, and on the whole the transaction was nowise disagreeable to me.
"On the Commemoration Day, December I5th, I received my Prize (Mitford's Greece) as First-Class man, after dinner in the College Hall. After a short vacation spent at Bury and Playford I returned to Cambridge, walking from Bury on Jan. 22nd, 1821. During the next term I find in Mathe- matics Partial Differential Equations, Tides, Sound, Calculus of Variations, Composition of rotary motions, Motion in resist- ing medium, Lhuillier's theorem, Brightness of an object as seen through a medium with any possible law of refraction (a good investigation), star-reductions, numerical calculations connected with them, equilibrium of chain under centripetal force (geometrically treated, as an improvement upon Whe-
32 GEORGE BIDDELL AIRY.
well's algebraical method), investigation of the magnitude of attractive forces of glass, &c., -required to produce refraction. I forget about Mathematical Lectures ; but I have an impres- sion that I regularly attended Mr Peacock's lectures, and that he always set me some private problems.
" I attended Mr Evans's lectures on St Luke : and I find many notes about the history of the Jews, Cerinthus and various heresies, Paley's Moral Philosophy, Paley's Evidences, and Biblical Maps : also speculations about ancient pronun- ciations.
"For a week or more before the annual examination I was perfectly lazy. The Classes of my year (Junior Sophs) were not published till June 11. It was soon known that I was first with 2000 marks, the next being Drinkwater with 1200 marks. After a short holiday at Bury and Playford I returned to Cambridge on July i8th, 1821. My daily life went on as usual. I find that in writing Latin I began Cicero De Senectute (retranslating Melmoth's translation, and comparing). Some time in the Long Vacation the names of the Prizemen for Declamations were published : I was disappointed that not one, English or Latin, was assigned to me: but it was foolish, for my declamations were rather trumpery.
"My former pupil, Rosser, came again on August I4th. On August 29th Dr Blomfield (afterwards Bishop of London) called, to engage me as Tutor to his brother George Beecher Blomfield, and he commenced attendance on Sept. ist. With these two pupils I finished at the end of the Long Vacation : for the next three terms I had one pupil, Gibson, a New- castle man, recommended by Mr Peacock, I believe, as a personal friend (Mr Peacock being of Durham).
" The only classical subject appointed for the next exami- nation was the 5th, 6th and /th Books of the Odyssey : the mathematical subjects all the Applied Mathematics and New- ton. There was to be however the Scholarship Examination (Sizars being allowed to sit for Scholarships only in their
FROM BIRTH TO B.A. DEGREE. 33
3rd year : and the Scholarship being a kind of little Fellow- ship necessary to qualify for being a candidate for the real Fellowship).
" When the October term began Mr Hustler, who usually gave lectures in mathematics to his third-year pupils, said to me that it was not worth my while to attend his lectures, and he or Mr Peacock suggested that Drinkwater, Myers, and I should attend the Questionists' examinations. The Ques- tionists are those who are to take the degree of B.A. in the next January : and it was customary, not to give them lectures, but three times a week to examine them by setting mathematical questions, as the best method of preparing for the B.A. examination. Accordingly it was arranged that we should attend the said examinations : but when we went the Questionists of that year refused to attend. They were reported to be a weak year, and we to be a strong one : and they were disposed to take offence at us on any occasion. From some of the scholars of our year who sat at table with scholars of that year I heard that they distinguished us as ' the impudent year,' ' the annus mirabilis,' &c. On this occasion they pretended to believe that the plan of our attendance at the Questionists' examinations had been sug- gested by an undergraduate, and no explanation was of the least use. So the Tutors agreed not to press the matter on them : and instead of it, Drinkwater, Myers, and I went three times a week to Mr Peacock's rooms, and he set us questions. I think that this system was also continued during the next two terms (ending in June 1822) or part of them, but I am not certain.
"In August 1821 I copied out a MS. on Optics, I think from Mr Whewell : on August 24th one on the Figure of the Earth and Tides ; and at some other time one on the motion of a body round two centers of force; both from Mr Whewell. On my scribbling paper I find— A problem on the vibrations of a gig as depending on the horse's step (like that of a pendulum whose support is disturbed), Maclaurin's Attrac-
A. B, 3
34 GEORGE BIDDELL AIRY.
tions, Effect of separating the lenses of an achromatic object- glass (suggested by my old ; "telescope), Barlow's theory of numbers, and division of the circle into 17 parts, partial differentials, theory of eye-pieces, epicycloids, Figure of the Earth, Time of body in arc of parabola, Problem of Sound, Tides, Refraction of Lens, including thickness, &c., Ivory's paper on Equations, Achromatism of microscope, Capillary Attraction, Motions of Fluids, Euler's principal
axes, Spherical pendulum, Equation fr -^ = -^ , barometer,
Lunar Theory well worked out, ordinary differential equa- tions, Calculus of Variations, Interpolations like Laplace's for Comets, Kepler's theorem. In September I had my old telescope mounted on a short tripod stand, and made experi- ments on its adjustments. I was possessed of White's Ephe- meris, and I find observations of Jupiter and Saturn in October. I planned an engine for describing ellipses by the
A
polar equation ~ , and tried to make a micrometer
I + e cos 0
with silk threads converging to a point. Mr Cubitt called on Oct. 4 and Nov. I ; he was engaged in erecting a tread- mill at Cambridge Gaol, and had some thoughts of sending plans for the Cambridge Observatory, the erection of which was then proposed. On Nov. 19 I find that I had received from Cubitt a Nautical Almanac, the first that I had. On Dec. ill made some experiments with Drinkwater : I think it was whirling a glass containing oil on water. In Classics I was chiefly engaged upon Thucydides and Homer. On October 6th I had a letter from Charles Musgrave, intro- ducing Challis, who succeeded me in the Cambridge Obser- vatory in 1836.
" At this time my poor afflicted father was suffering much from a severe form of rheumatism or pain in the legs which sometimes prevented him from going to bed for weeks together.
"On the Commemoration Day, Dec. i8th, I received my
FROM BIRTH TO B.A. DEGREE. 35
prize as first-class man in Hall again. The next day I walked to Bury, and passed the winter vacation there and at Playford.
"I returned to Cambridge on Jan. 24th, 1822. On Feb. 1 2th I kept my first Act, with great compliments from the Moderator, and with a most unusually large attendance of auditors. These disputations on mathematics, in Latin, are now discontinued. On March 2Oth I kept a first Opponency against Sandys. About this time I received Buckle, a Trinity man of my own year, who was generally supposed to come next after Drinkwater, as pupil. On my sheets I find inte- grals and differential equations of every kind, astronomical corrections (of which I prepared a book), chances, Englefield's comets, investigation of the brightness within a rainbow, proof of Clairaut's theorem in one case, metacentres, change of independent variable applied to a complicated case, gene- rating functions, principal axes. On Apr. 8th I intended to write an account of my eye : I was then tormented with a double image, I suppose from some disease of the stomach : and on May 28th I find by a drawing of the appearance of a lamp that the disease of my eye continued.
" On Feb. i ith I gave Mr Peacock a paper on the alteration of the focal length of a telescope as directed with or against the Earth's orbital motion (on the theory of emissions) which was written out for reading to the Cambridge Philosophical Society on Feb. 24th and 25th. [This Society I think was then about a year old.] On Feb. I my MS. on Precession, Solar Inequality, and Nutation, was made complete.
" The important examination for Scholarships was now approaching. As I have said, this one opportunity only was given to Sizars (Pensioners having always two opportunities and sometimes three), and it is necessary to be a Scholar in order to be competent to be a candidate for a Fellowship. On Apr. loth I addressed my formal Latin letter to the Seniors. There were 13 vacancies and 37 candidates. The election took place on Apr. i8th, 1822. I was by much
3—2
36 GEORGE BIDDELL AIRY.
the first (which I hardly expected) and was complimented by the Master and others. Wrote; the formal letter of thanks as usual. I was now entitled to claim better rooms, and I took the rooms on the ground floor on the East sicje of the Queen's Gate of the Great Court. Even now I think of my quiet residence in the little rooms above the staircase in Neville's Court with great pleasure. I took possession of my new rooms on May 27th.
"The Annual Examination began on May 3<Dth. The Classes were published on June 5th, when my name was sepa- rated from the rest by two lines. It was understood that the second man was Drinkwater, and that my number of marks was very nearly double of his. Having at this time been disap- pointed of a proposed walking excursion into Derbyshire with a college friend, who failed me at the last moment, I walked to Bury and spent a short holiday there and at Playford.
"I returned to Cambridge on July I2th, 1822. I was steadily busy during this Long Vacation, but by no means oppressively so : indeed my time passed very happily. The Scholars' Table is the only one in College at which the regular possessors of the table are sure never to see a stranger, and thus a sort of family intimacy grows up among the Scho- lars. Moreover the Scholars feel themselves to be a privileged class ' on the foundation/ and this feeling gives them a sort of conceited happiness. It was the duty of Scholars by turns to read Grace after the Fellows' dinner and supper, and at this time (1848) I know it by heart. They also read the Lessons in Chapel on week days : but as there was no daily chapel-service during the summer vacation, I had not much of this. In the intimacy of which I speak I became much acquainted with Drinkwater, Buckle, Rothman, and Sutcliffe : and we formed a knot at the table (first the Undergraduate Scholars' table, and afterwards the Bachelor Scholars' table) for several years. During this Vacation I had for pupils Buckle and Gibson.
" I wrote my daily Latin as usual, beginning with the
FROM BIRTH TO B.A. DEGREE. 37
retranslation of Cicero's Epistles, but I interrupted it from Sept. 27th to Feb. 8th. I believe it was in this Vacation, or in the October term, that I began every evening to read Thucydides very carefully, as my notes are marked 1822 and 1823. On August 27 I find that I was reading Ovid's Fasti.
"In Mathematics I find the equation x+y=a, x? +y? = by Caustics, Calculus of Variations, Partial Differentials, Aberra- tion of Light, Motions of Comets, various Optical construc- tions computed with spherical aberrations, Particular Solu- tions, Mechanics of Solid Bodies, Attractions of Shells, Chances, Ivory's attraction-theorem, Lunar Theory (alge- braical), Degrees across meridian, theoretical refraction, Newton's 3rd Book, Investigation of the tides in a shallow equatoreal canal, from which I found that there would be low-water under the moon, metacentres, rotation of a solid body round three axes, Attractions of Spheroids of variable density, finite differences, and complete Figure of the Earth. There is also a good deal of investigation of a mathematical nature not connected with College studies, as musical chords, organ-pipes, sketch for a computing machine (suggested by the publications relating to Babbage's), sketch of machine for solving equations. In August there is a plan of a MS. on the Differential Calculus, which it appears I wrote then : one on the Figure of the Earth written about August I5th; one on Tides, Sept. 25th ; one on Newton's Principia with algebraical additions, Nov. 1st. On Sept. 6th and loth there are Lunar Distances observed with Rothman's Sextant and completely worked out ; for these I prepared a printed skeleton form, I believe my first. On December I3th there are references to books on Geology (Conybeare and Phillips, and Parkinson) which I was beginning to study. On July 27th, being the day on which I completed my 2ist year, I carefully did nothing.
" Another subject partly occupied my thoughts, which, though not (with reference to practical science) very wise, yet gave me some Cambridge celebrity. In July 1819 I had (as before mentioned) sketched a plan for constructing
38 GEORGE BIDDELL AIRY.
reflecting telescopes with silvered glass, and had shewn it afterwards to Mr Peacock. I "now completed the theory of this construction by correcting the aberrations, spherical as well as chromatic. On July I3th, 1822, I drew up a paper about it for Mr Peacock. He approved it much, and in some way communicated it to Mr (afterwards Sir John) Herschel. I was soon after introduced to Herschel at a breakfast with Mr Peacock : and he approved of the scheme generally. On August 5th I drew up a complete mathematical paper for the Cambridge Philosophical Society, which I entrusted to Mr Peacock. The aberrations, both spherical and chromatic, are here worked out very well. On Nov. 25th it was read at the meeting of the Philosophical Society, and was afterwards printed in their Transactions: this was my first printed Memoir. Before this time however I had arranged to try the scheme practically. Mr Peacock had engaged to bear the expense, but I had no occasion to ask him. Partly (I think) through Drinkwater, I communicated with an optician named Bancks, in the Strand, who constructed the optical part. I subsequently tried my telescope, but it would not do. The fault, as I had not and have not the smallest doubt, depends in some way on the crystallization of the mercury silvering. It must have been about this time that I was introduced to Mr (afterwards Sir James) South, at a party at Mr Peacock's rooms. He advised me to write to Tulley, a well-known practical optician, who made me some new reflectors, &c. (so that I had two specimens, one Gregorian, the other Cassegrainian). However the thing failed practi- cally, and I was too busy ever after to try it again.
" During the October term I had no pupils. I kept my second Act on Nov. 6 (opponents Hamilton, Rusby, Field), and an Opponency against Jeffries on Nov. 7. I attended the Questionists' Examinations. I seem to have lived a very comfortable idle life. The Commemoration Day was Dec. 1 8th, when I received a Prize, and the next day I walked to Bury. On Jan. 4th, 1823, I returned to Cambridge, and
FROM BIRTH TO B.A. DEGREE. 39
until the B.A. Examination I read novels and played cards more than at any other time in College.
"On Thursday, Jan. 9th, 1823, the preliminary classes, for arrangement of details of the B.A. Examination, were pub- lished. The first class, Airy, Drinkwater, Jeffries, Mason. As far as I remember, the rule was then, that on certain days the classes were grouped (in regard to identity of questions
given to each group) thus: ist, \ — -r> , -j^-rl , &c., and on
certain other days thus: \ — . ' 2nd
ist
3rd
&c. On Saturday,
Jan. i ith, I paid fees. On Monday, Jan. I3th, the proceedings of examination began by a breakfast in the Combination Room. After this, Gibson gave me breakfast every day, and Buckle gave me and some others a glass of wine after dinner. The hours were sharp, the season a cold one, and no fire was allowed in the Senate House where the Examination was carried on (my place was in the East gallery), and altogether it was a severe time.
" The course of Examination was as follows :
"Monday, Jan. I3th. 8 to 9, printed paper of questions by Mr Hind (moderator); half-past 9 to II, questions given orally ; I to 3, ditto ; 6 to 9, paper of problems at Mr Hig- man's rooms.
" Tuesday, Jan. I4th. 8 to 9, Higman's paper; half-past 9 to n, questions given orally ; I to 3, ditto ; 6 to 9, paper of problems in Sidney College Hall.
"Wednesday, Jan. I5th. Questions given orally 8 to 9 and I to 3, with paper of questions on Paley and Locke (one question only in each was answered).
"Thursday, Jan. i6th. We went in at 9 and I, but there seems to have been little serious examination.
" Friday, Jan. i/th. On this day the brackets or classes as resulting from the examination were published, ist bracket Airy, 2nd bracket Jeffries, 3rd bracket Drinkwater, Fisher, Foley, Mason, Myers.
40 GEORGE BIDDELL AIRY.
" On Saturday, Jan. i8th, the degrees were conferred in the usual way. It had been arranged that my brother and sister should come to see me take my degree of B.A., and I had asked Gibson to conduct them to the Senate House Gallery : but Mr Hawkes (a Trinity Fellow) found them and stationed them at the upper end of the Senate House. After the preliminary arrangements of papers at the Vice-Chancellor's table, I, as Senior Wrangler, was led up first to receive the degree, and rarely has the Senate House rung with such applause as then filled it. For many minutes, after I was brought in front of the Vice-Chancellor, it was impossible to proceed with the ceremony on account of the uproar. I gave notice to the Smith's Prize Electors of my intention to ' sit ' for that prize, and dined at Rothman's rooms with Drink- water, Buckle, and others. On Monday, Jan. 2Oth, I was examined by Professor Woodhouse, for Smith's Prize, from 10 to i. I think that the only competitor was Jeffries. On Tuesday I was examined by Prof. Turton, 10 to i, and on Wednesday by Prof. Lax, 10 to I. On Thursday, Jan. 23rd, I went to Bury by coach, on one of the coldest evenings that I ever felt.
" Mr Peacock had once recommended me to sit for the Chancellor's medal (Classical Prize). But he now seemed to be cool in his advice, and I laid aside all thought of it."
It seems not out of place to insert here a copy of some "Cambridge Reminiscences" written by Airy, which will serve to explain the Acts and Opponencies referred to in the previous narrative, and other matters.
THE ACTS.
The examination for B.A. degrees was preceded, in my time, by keeping two Acts, in the Schools under the Univer- sity Library: the second of them in the October term imme-
FROM BIRTH TO B.A. DEGREE. 41
diately before the examination ; the first (I think) in the October term of the preceding year.
These Acts were reliques of the Disputations of the Middle Ages, which probably held a very important place in the discipline of the University. (There seems to be something like them in some of the Continental Universities.) The presiding authority was one of the Moderators. I appre- hend that the word " Moderator " signified " President," in which sense it is still used in the Kirk of Scotland ; and that it was peculiarly applied to the Presidency of the Disputa- tions, the most important educational arrangement in the University. The Moderator sent a summons to the " Re- spondent" to submit three subjects for argument, and to prepare to defend them on a given day : he also named three Opponents. This and all the following proceedings were conducted in Latin. For my Act of 1822, Nov. 6, I sub- mitted the following subjects :
" Recte statuit Newtonus in Principiis suis Mathematicis, libro primo, sectione undecima."
" Recte statuit Woodius de Iride."
" Recte statuit Paleius de Obligationibus."
The Opponents named to attack these assertions were Hamilton of St John's, Rusby of St Catharine's, Field of Trinity. It was customary for the Opponents to meet at tea at the rooms of the Senior Opponent, in order to discuss and arrange their arguments ; the Respondent was also invited, but he was warned that he must depart as soon as tea would be finished : then the three Opponents proceeded with their occupation. As I have acted in both capacities, I am able to say that the matter was transacted in an earnest and business- like way. Indeed in the time preceding my own (I know not whether in my own time) the assistance of a private tutor was frequently engaged, and I remember hearing a senior M.A. remark that my College Tutor (James D. Hustler) was the best crammer for an Act in the University.
At the appointed time, the parties met in the Schools :
42 GEORGE BIDDELL AIRY.
the Respondent first read a Latin Thesis on any subject (I think I took some metaphysical subject), but nobody paid any attention to it: then the Respondent read his first Dogma, and the first Opponent produced an argument against it, in Latin. After this there were repeated replies and rejoinders, all in viva voce Latin, the Moderator sometimes interposing a remark in Latin. When he considered that one argument was disposed of, he called for another by the words " Probes aliter." The arguments were sometimes shaped with con- siderable ingenuity, and required a clear head in the Respon- dent. When all was finished, the Moderator made a compli- mentary remark to the Respondent and one to the first Opponent (I forget whether to the second and third). In my Respondency of 1822, November 6, the compliment was, " Quaestiones tuas summo ingenio et acumine defendisti, et in rebus mathematicis scientiam plane mirabilem ostendisti.' In an Opponency (I forget when) the compliment was, " Magno ingenio argumenta tua et construxisti et defen- disti."
The Acts of the high men excited much interest among the students. At my Acts the room was crowded with undergraduates.
I imagine that, at a time somewhat distant, the mainte- nance of the Acts was the only regulation by which the University acted on the studies of the place. When the Acts had been properly kept, license was given to the Father of the College to present the undergraduate to the Vice- Chancellor, who then solemnly admitted him "ad respon- dendum Quaestioni." There is no appearance of collective examination before this presentation : what the " Quaestio " might be, I do not know. Still the undergraduate was not B.A. The Quaestio however was finished and approved before the day of a certain Congregation, and then the under- graduate was declared to be "actualiter in artibus Bacca- laureum."
Probably these regulations were found to be insufficient
FROM BIRTH TO B.A. DEGREE. 43
for the control of education, and the January examination was instituted. I conjecture this to have been at or shortly before the date of the earliest Triposes recorded in the Cambridge Calendar, 1748.
The increasing importance of the January examination naturally diminished the value of the Acts in the eyes of the undergraduates ; and, a few years after my M.A. degree, it was found that the Opponents met, not for the purpose of concealing their arguments from the Respondent, but for the purpose of revealing them to him. This led to the entire suppression of the system. The most active man in this suppression was Mr Whewell : its date must have been near to 1830.
The shape in which the arguments were delivered by an Opponent, reading from a written paper, was, " Si (quoting something from the Respondent's challenge), &c., &c. Cadit Quaestio ; Sed (citing something else bearing on the subject of discussion), Valet Consequentia ; Ergo (combining these to prove some inaccuracy in the Respondent's challenge), Valent Consequentia et Argumentum." Nobody pretended to understand these mystical terminations.
Apparently the original idea was that several Acts should be kept by each undergraduate ; for, to keep up the number (as it seemed), each student had to gabble through a ridicu- lous form " Si quaestiones tuae falsae sint, Cadit Quaestio : — sed quaestiones tuae falsae sunt, Ergo valent Consequentia et Argu- mentum." I have forgotten time and place when this was uttered.
THE SENATE-HOUSE EXAMINATION.
The Questionists, as the undergraduates preparing for B.A. were called in the October term, were considered as a separate body; collected at a separate table in Hall, attending no lectures, but invited to attend a system of trial examina- tions conducted by one of the Tutors or Assistant-Tutors.
44 GEORGE BIDDELL AIRY.
From the Acts, from the annual College examinations, and (I suppose) from enquiries' in the separate Colleges, the Moderators acquired a general idea of the relative merits of the candidates for honours. Guided by this, the candidates were divided into six classes. The Moderators and Assistant Examiners were provided each with a set of questions in manuscript (no printed papers were used for Honours in the Senate House ; in regard to the ol TroXXol I cannot say). On the Monday on which the examination began, the Father of the College received all the Questionists (I believe), at any rate all the candidates for honours, at breakfast in the Combi- nation Room at 8 o'clock, and marched them to the Senate House. My place with other honour-men was in the East Gallery. There one Examiner took charge of the 1st and 2nd classes united, another Examiner took the 3rd and 4th classes united, and a third took the 5th and 6th united. On Tuesday, one Examiner took the ist class alone, a second took the 2nd and 3rd classes united, a third took the 4th and 5th classes united, and a fourth took the 6th class alone. On Wednesday, Thursday, and Friday the changes were similar. And, in all, the questioning was thus conducted. The Examiner read from his manuscript the first question. Those who could answer it proceeded to write out their answers, and as soon as one had finished he gave the word "Done"; then the Examiner read out his second question, repeating it when necessary for the understanding by those who took it up more lately. And so on. I think that the same process was repeated in the afternoon ; but I do not remember precisely. In this manner the Examination was conducted through five days (Monday to Friday) with no interruption except on Friday afternoon. It was principally, perhaps entirely, bookwork.
But on two evenings there were printed papers of prob- lems: and the examination in these was conducted just as in the printed papers of the present day : but in the private College Rooms of the Moderators. And there, wine and
FROM BIRTH TO B.A. DEGREE. 45
other refreshments were offered to the Examinees. How this singular custom began, I know not.
The order of merit was worked out on Friday afternoon and evening, and was in some measure known through the University late in the evening. I remember Mr Peacock coming to a party of Examinees and giving information on several places. I do not remember his mentioning mine (though undoubtedly he did) but I distinctly remember his giving the Wooden Spoon. On the Saturday morning at 8 o'clock the manuscript list was nailed to the door of the Senate-House. The form of further proceedings in the pre- sentation for degree (ad respondendum quaestioni) I imagine has not been much altered. The kneeling before the Vice- Chancellor and placing hands in the Vice-Chancellor's hands were those of the old form of doing homage.
The form of examination which I have described was complicated and perhaps troublesome, but I believe that it was very efficient, possibly more so than the modern form (established I suppose at the same time as the abolition of the Acts). The proportion of questions now answered to the whole number set is ridiculously small, and no accurate idea of relative merit can be formed from them.
THE COLLEGE HALL.
When I went up in 1819, and for several years later, the dinner was at J past 3. There was no supplementary dinner for special demands. Boat-clubs I think were not invented, even in a plain social way, till about 1824 or 1825; and not in connection with the College till some years later. Some of the senior Fellows spoke of the time when dinner was at 2, and regretted the change.
There was supper in Hall at 9 o'clock : I have known it to be attended by a few undergraduates when tired by ex- aminations or by evening walks; and there were always some seniors at the upper table: I have occasionally joined them,
46 GEORGE BIDDELL AIRY.
and have had some very interesting conversations. The supper was cold, but hot additions were made when re- quired.
One little arrangement amused me, as shewing the ecclesiastical character of the College. The Fasts of the Church were to be strictly kept, and there was to be no dinner in Hall. It was thus arranged. The evening chapel service, which was usually at 5^ (I think), was held at 3; and at 4 the ordinary full meal was served in Hall, but as it followed the chapel attendance it was held to be supper; and there was no subsequent meal.
There were no chairs whatever in Hall, except the single chair of the vice-master at the head of the table on the dais and that of the senior dean at the table next the East wall. All others sat on benches. And I have heard allusions to a ludicrous difficulty which occurred when some princesses (of the Royal Family) dined in the Hall, and it was a great puzzle how to get them to the right side of the benches.
The Sizars dined after all the rest; their dinner usually began soon after 4. For the non-foundationists a separate dinner was provided, as for pensioners. But for the founda- tionists, the remains of the Fellows' dinner were brought down ; and I think that this provision was generally preferred to the other.
The dishes at all the tables of undergraduates were of pewter, till a certain day when they were changed for porce- lain. I cannot remember whether this was at the time when they became Questionists (in the October Term), or at the time when they were declared "actualiter esse in artibus Baccalaureos " (in the Lent Term).
Up to the Questionist time the undergraduate Scholars had no mixture whatever; they were the only pure table in the Hall : and I looked on this as a matter very valuable for the ultimate state of the College society. But in the October term, those who were to proceed to B.A. were drafted into the mixed body of Questionists : and they greatly disliked
FROM BIRTH TO B.A. DEGREE. 47
the change. They continued so till the Lent Term, when they, were formally invited by the Bachelor Scholars to join the upper table.
MATHEMATICAL SUBJECTS OF STUDY AND EXAMINATION.
In the October Term 1819, the only books on Pure Mathematics were: — Euclid generally, Algebra by Dr Wood (formerly Tutor, but in 1819 Master, of St John's College), Vince's Fluxions and Dealtry's Fluxions, Woodhouse's and other Trigonometries. Not a whisper passed through the University generally on the subject of Differential Calculus ; although some papers (subsequently much valued) on that subject had been written by Mr Woodhouse, fellow of Caius College ; but their style was repulsive, and they never took hold of the University. Whewell's Mechanics (1819) contains a few and easy applications of the Differential Calculus. The books on applied Mathematics were Wood's Mechanics, Whewell's Mechanics, Wood's Optics, Vince's Hydrostatics, Vince's Astronomy, Woodhouse's Plane Astronomy (perhaps rather later), The First Book of Newton's Principia: I do not remember any others. These works were undoubtedly able; and for the great proportion of University students going into active life, I do not conceal my opinion that books con- structed on the principles of those which I have cited were more useful than those exclusively founded on the more modern system. For those students who aimed at the mastery of results more difficult and (in the intellectual sense) more important, the older books were quite insufficient. More aspiring students read, and generally with much care, several parts of Newton's Principia, Book I., and also Book III. (perhaps the noblest example of geometrical form of cosmical theory that the world has seen). I remember some questions from Book III. proposed in the Senate-House Examination 1823.
48 GEORGE BIDDELL AIRY.
In the October term 1819, I went up to the University. The works of Wood and Vince* which I have mentioned, still occupied the lecture-rooms. But a great change was in preparation for the University Course of Mathematics. During the great Continental war, the intercourse between men of science in England and in France had been most insignificant. But in the autumn of 1819, three members of the Senate (John Herschel, George Peacock, and Charles Babbage) had entered into the mathematical society of Paris, and brought away some of the works on Pure Mathematics (especially those of Lacroix) and on Mechanics (principally Poisson's). In 1820 they made a translation of Lacroix's Differential Calculus ; and they prepared a volume of Ex- amples of the Differential and Integral Calculus. These were extensively studied : but the form of the College Ex- aminations or the University Examinations was not, I think, influenced by them in the winter 1820 — 1821 or the two following terms. But in the winter 1821 — 1822 Peacock was one of the Moderators ; and in the Senate-House Examina- tion, January 1822, he boldly proposed a Paper of important questions entirely in the Differential Calculus. This was considered as establishing the new system in the University. In January 1823, I think the two systems were mingled. Though I was myself subject to that examination, I grieve to say that I have forgotten much of the details, except that I well remember that some of the questions referred to Newton, Book III. on the Lunar Theory. To these I have already alluded.
No other work occurs to me as worthy of mention, except Woodhouse's Lunar Theory, entirely founded on the Dif- ferential Calculus. The style of this book was not attractive, and it was very little read.
CHAPTER III.
AT TRINITY COLLEGE, CAMBRIDGE, FROM HIS TAKING HIS B.A. DEGREE TO HIS TAKING CHARGE OF THE CAMBRIDGE OBSERVATORY AS PLUMIAN PROFESSOR.
FROM JANUARY ISTH, 1823, TO MARCH ISTH, 1828.
"ON Jan. 3<Dth, 1823, I returned to Cambridge. I had already heard that I had gained the 1st Smith's Prize, and one of the first notifications to me on my return was that the Walker's good-conduct prize of £10 was awarded to me.
" I remember that my return was not very pleasant, for our table in hall was half occupied by a set of irregular men who had lost terms and were obliged to reside somewhat longer in order to receive the B.A. degree. But at the time of my completing the B.A. degree (which is not till some weeks after the examination and admission) I with the other com- plete bachelors was duly invited to the table of the B.A. scholars, and that annoyance ended.
"The liberation from undergraduate study left me at liberty generally to pursue my own course (except so far as it was influenced by the preparation for fellowship examination), and also left me at liberty to earn more money, in the way usual with the graduates, by taking undergraduate pupils. Mr Peacock recommended me to take only four, which occupied me four hours every day, and for each of them I received 20 guineas each term. My first pupils, for the Lent and Easter terms, were Williamson (afterwards Head Master of Westminster School), James Parker (afterwards Q.C. and A. B. 4
50 GEORGE BIDDELL AIRY.
Vice-Chancellor), Bissett, and Clinton of Caius. To all these I had been engaged before taking my B.A. degree.
" I kept up classical subjects. I have a set of notes on the nXouro? and Ne<£e\a* of Aristophanes, finished on Mar. 1 5th, 1823, and I began my daily writing of Latin as usual on Feb. 8th. In mathematics I worked very hard at Lunar and Planetary Theories. I have two MS. books of Lunar Theory to the 5th order of small quantities, which however answered no purpose except that of making me perfectly familiar with that subject. I worked well, upon my quires, the figure of Saturn supposed homogeneous as affected by the attraction of his ring, and the figure of the Earth as heterogeneous, and the Calculus of Variations. I think it was now that I wrote a MS. on constrained motion.
"On Mar. i;th, 1823, I was elected Fellow of the Cam- bridge Philosophical Society. On May Qth a cast of my head was taken for Dr Elliotson, an active phrenologist, by Deville, a tradesman in the Strand.
" I had long thought that I should like to visit Scotland, and on my once saying so to my mother, she (who had a most kindly recollection of Alnwick) said in a few words that she thought I could not do better. I had therefore for some time past fully determined that as soon as I had sufficient spare time and money enough I would go to Scotland. The interval between the end of Easter Term and the usual beginning with pupils in the Long Vacation offered sufficient time, and I had now earned a little money, and I therefore determined to go, and invited my sister to accompany me. I had no private introductions, except one from James Parker to Mr Reach, a writer of Inverness : some which Drinkwater sent being too late. On May 2Oth we went by coach to Stamford ; thence by Pontefract and Oulton to York, where I saw the Cathedral, which then disappointed me, but I suppose that we were tired with the night journey. Then by Newcastle to Alnwick, where we stopped for the day to see my birth- place. On May 24th to Edinburgh. On this journey I
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 51
remember well the stone walls between the fields, the place (in Yorkshire) where for the first time in my life I saw rock, the Hambleton, Kyloe, Cheviot and Pentland Hills, Arthur's Seat, but still more strikingly the revolving Inch Keith Light. At Edinburgh I hired a horse and gig for our journey in Scotland, and we drove by Queensferry to Kinross (where for the first time in my life I saw clouds on the hills, viz. on the Lomond Hills), and so to Perth. Thence by Dunkeld and Killicrankie to Blair Athol (the dreariness of the Drumochter Pass made a strong impression on me), and by Aviemore (where I saw snow on the mountains) to Inverness. Here we received much kindness and attention from Mr Reach, and after visiting the Falls of Foyers and other sights we went to Fort Augustus and Fort William. We ascended Ben Nevis, on which there was a great deal of snow, and visited the vitrified fort in Glen Nevis. Then by Inverary to Tarbet, and ascended Ben Lomond, from whence we had a magnifi- cent view. We then passed by Loch Achray to Glasgow, where we found James Parker's brother (his father, of the house of Macinroy and Parker, being a wealthy merchant of Glasgow). On June I5th to Mr Parker's house at Blochairn, near Glasgow (on this day I heard Dr Chalmers preach), and on the i /th went with the family by steamer (the first that I had seen) to Fairly, near Largs. I returned the gig to Edin- burgh, visited Arran and Bute, and we then went by coach to Carlisle, and by Penrith to Keswick (by the old road : never shall I forget the beauty of the approach to Keswick). After visiting Ambleside and Kendal we returned to Cambridge by way of Leeds, and posted to Bury on the 28th June. The expense of this expedition was about £81. It opened a com- pletely new world to me.
" I had little time to rest at Bury. In the preceding term Drinkwater, Buckle, and myself, had engaged to go some- where into the country with pupils during the Long Vacation (as was customary with Cambridge men). Buckle however changed his mind. Drinkwater went to look for a place,
4—2
52 GEORGE BIDDELL AIRY.
fixed on Swansea, and engaged a house (called the Cambrian Hotel, kept by a Captain Jenkins). On the morning of July 2nd I left Bury for London and by mail coach to Bristol. On the morning of July 3rd by steamer to Swansea, and arrived late at night. I had then five pupils: Parker, Harman Lewis (afterwards Professor in King's College, Lon- don), Pierce Morton, Gibson, and Guest of Caius (afterwards Master of the College). Drinkwater had four, viz. two Malkins (from Bury), Elphinstone (afterwards M.P.), and Parish (son of Professor Parish). We lived a hard-working strange life. My pupils began with me at six in the morning : I was myself reading busily. We lived completely enfamille, with two men-servants besides the house establishment. One of our first acts was to order a four-oared boat to be built, fitted with a lug-sail : she was called the Granta of Swansea. In the meantime we made sea excursions with boats borrowed from ships in the port. On July 23rd, with a borrowed boat, we went out when the sea was high, but soon found our boat unmanageable, and at last got into a place where the sea was breaking heavily over a shoal, and the two of the crew who were nearest to me (A. Malkin and Lewis), one on each side, were carried out : they were good swimmers and we recovered them, though with some trouble : the breaker had passed quite over my head : we gained the shore and the boat was taken home by land. When our own boat was finished, we had some most picturesque adventures at the Mumbles, Aberavon, Caswell Bay, Ilfracombe, and Tenby. From all this I learnt navigation pretty well. The mixture of hard study and open-air exertion seemed to affect the health of several of us (I was one) : we were covered with painful boils. " My Latin-writing began again on July 25th : I have notes on Demosthenes, Lucretius, and Greek History. In mathe- matics I find Chances, Figure of the Earth with variable density, Differential Equations, Partial Differentials, sketch for an instrument for shewing refraction, and Optical instru- ments with effects of chromatic aberration. In August there
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 53
occurred an absurd quarrel between the Fellows of Trinity and the undergraduates, on the occasion of commencing the building of King's Court, when the undergraduates were not invited to wine, and absented themselves from the hall.
"There were vacant this year (1823) five fellowships in Trinity College. In general, the B.A.'s of the first year are not allowed to sit for fellowships : but this year it was thought so probable that permission would be given, that on Sept. 2nd Mr Higman, then appointed as Tutor to a third ' side ' of the College, wrote to me to engage me as Assistant Mathematical Tutor in the event of my being elected a Fellow on Oct. ist, and I provisionally engaged myself. About the same time I had written to Mr Peacock, who recommended me to sit, and to Mr Whewell, who after con- sultation with the Master (Dr Wordsworth), discouraged it. As there was no absolute prohibition, I left Swansea on Sept. nth (before my engagement to my pupils was quite finished) and returned to Cambridge by Gloucester, Oxford, and London. I gave in my name at the butteries as candidate for fellowship, but was informed in a day or two that I should not be allowed to sit. On Sept. ipth I walked to Bury.
" I walked back to Cambridge on Oct. i/th, 1823. During this October term I had four pupils : Neate, Cankrein, Turner (afterwards 2nd wrangler and Treasurer of Guy's Hospital), and William Hervey (son of the Marquis of Bristol). In the Lent term I had four (Neate, Cankrein, Turner, Clinton). In the Easter term I had three (Neate, Cankrein, Turner).
" My daily writing of Latin commenced on Oct. 27th. In November I began re-reading Sophocles with my usual care. In mathematics I find investigations of Motion in a resisting medium, Form of Saturn, Draft of a Paper about an instru- ment for exhibiting the fundamental law of refraction (read at the Philosophical Society by Mr Peacock on Nov. loth, 1823), Optics, Solid Geometry, Figure of the Earth with variable density, and much about attractions. I also in this term wrote a MS. on the Calculus of Variations, and one on
54 GEORGE BIDDELL AIRY.
Wood's Algebra, 2nd and 4th parts. I have also notes of the temperature of mines in Cornwall, something on the light of oil-gas, and reminiscences of Swansea in a view of Oswick Bay. In November I attended Professor Sedgwick's geo- logical lectures.
"At some time in this term I had a letter from Mr South (to whom I suppose I had written) regarding the difficulty of my telescope : he was intimately acquainted with Tulley, and I suppose that thus the matter had become more fully known to him. He then enquired if I could visit him in the winter vacation. I accordingly went from Bury, and was received by him at his house in Blackman Street for a week or more with great kindness. He introduced me to Sir Humphrey Davy and many other London savans, and shewed me many London sights and the Greenwich Observatory. I also had a little practice with his own instruments. He was then on intimate terms with Mr Herschel (afterwards Sir John Her- schel), then living in London, who came occasionally to observe double stars. This was the first time that I saw practical astronomy. It seems that I borrowed his mountain barometer. In the Lent term I wrote to him regarding the deduction of the parallax of Mars, from a comparison of the relative positions of Mars and 46 Leonis, as observed by him and by Rumker at Paramatta. My working is on loose papers. I see that I have worked out perfectly the interpo- lations, the effects of uncertainty of longitude, &c., but I do not see whether I have a final result.
" In Jan. 1824, at Playford, I was working on the effects of separating the two lenses of an object-glass, and on the kind of eye-piece which would be necessary : also on spherical aberrations and Saturn's figure. On my quires at Cambridge I was working on the effects of separating the object-glass lenses, with the view of correcting the secondary spectrum : and on Jan. 3ist I received some numbers (indices of refraction) from Mr Herschel, and reference to Fraunhofer's numbers.
" About this time it was contemplated to add to the Royal
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 55
Observatory of Greenwich two assistants of superior educa- tion. Whether this scheme was entertained by the Admiralty, the Board of Longitude, or the Royal Society, I do not know. Somehow (I think through Mr Peacock) a message from Mr Herschel was conveyed to me, acquainting me of this, and suggesting that I should be an excellent person for the prin- cipal place. To procure information, I went to London on Saturday, Feb. 7th, sleeping at Mr South's, to be present at one of Sir Humphrey Davy's Saturday evening soirees (they were then held every Saturday), and to enquire of Sir H. Davy and Dr Young. When I found that succession to the post of Astronomer Royal was not considered as distinctly a consequence of it, I took it coolly, and returned the next night. The whole proposal came to nothing.
" At this time I was engaged upon differential equations, mountain barometer problem and determination of the height of the Gogmagogs and several other points, investigations connected with Laplace's calculus, spherical aberration in different planes, geology (especially regarding Derbyshire, which I proposed to visit), and much of optics. I wrote a draft of my Paper on the figure of Saturn, and on Mar. I5th, 1824, it was read at the Philosophical Society under the title of ' On the figure assumed by a fluid homogeneous mass, whose particles are acted on by their mutual attraction, and by small extraneous forces,' and is printed in their Memoirs. I also wrote a draft of my Paper on Achromatic Eye-pieces, and on May i^th, 1824, it was read at the Philosophical Society under the title of 'On the Principles and Construc- tion of the Achromatic Eye-pieces of Telescopes, and on the Achromatism of Microscopes,' including also the effects of separating the lenses of the object-glass. It is printed in their Memoirs.
"Amongst miscellaneous matters I find that on Mar. 22nd of this year I began regularly making extracts from the books of the Book Society, a practice which I continued to March 1826. On Mar. 27th, a very rainy day, I walked to
56 GEORGE BIDDELL AIRY.
Bury to attend the funeral of my uncle William Biddell, near Diss, and on Mar. 3Oth I walked back in rain and snow. On Feb. 24th I dined with Cubitt in Cambridge. On May 2ist I gave a certificate to Rogers (the assistant in Crosse's school, and my instructor in mathematics), which my mother ampli- fied much, and which I believe procured his election as master of Walsall School. On June 23rd I went to Bury. The speeches at Bury School, which I wished to attend, took place next day."
At this point of his Autobiography the writer continues, " Now came one of the most important occurrences in my life." The important event in question was his acquaintance with Richarda Smith, the lady who afterwards became his wife. The courtship was a long one, and in the Auto- biography there are various passages relating to it, all written in the most natural and unaffected manner, but of somewhat too private a nature for publication. It will therefore be convenient to digress from the straight path of the narrative in order to insert a short memoir of the lady who was destined to influence his life and happiness in a most important degree.
Richarda Smith was the eldest daughter of the Rev. Richard Smith, who had been a Fellow of Trinity College, Cambridge, but was at this time Private Chaplain to the Duke of Devonshire, and held the small living of Edensor, near Chatsworth, in Derbyshire. He had a family of two sons and seven daughters, whom he had brought up and educated very carefully. Several of his daughters were remarkable both for their beauty and accomplishments. Richarda Smith was now in her 2Oth year, and the writer of the Autobiography records that "at Matlock we received great attention from Mr Chenery : in speaking of Mr Smith I remember his saying that Mr Smith had a daughter whom the Duke of Devonshire declared to be the most beautiful girl he ever saw." This was before he had made the acquaint- ance of the family. Airy was at this time on a walking
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 57
tour in Derbyshire with his brother William, and they were received at Edensor by Mr Smith, to whom he had letters of introduction. He seems to have fallen in love with Miss Smith " at first sight," and within two days of first seeing her he made her an offer of marriage. Neither his means nor his prospects at that time permitted the least idea of an imme- diate marriage, and Mr Smith would not hear of any engage- ment. But he never had the least doubt as to the wisdom of the choice that he had made : he worked steadily on, winning fame and position, and recommending his suit from time to time to Miss Smith as opportunity offered, and finally mar- ried her, nearly six years after his first proposal. His con- stancy had its reward, for he gained a most charming and affectionate wife. As he records at the time of his marriage, "My wife was aged between 25 and 26, but she scarcely appeared more than 18 or 20. Her beauty and accomplish- ments, her skill and fidelity in sketching, and above all her exquisite singing of ballads, made a great sensation in Cam- bridge."
Their married life lasted 45 years, but the last six years were saddened by the partial paralysis and serious illness of Lady Airy. The entire correspondence between them was most carefully preserved, and is a record of a most happy union. The letters were written during his numerous journeys and excursions on business or pleasure, and it is evident that his thoughts were with her from the moment of their parting. Every opportunity of writing was seized with an energy and avidity that shewed how much his heart was in the corre- spondence. Nothing was too trivial or too important to communicate to his wife, whether relating to family or business matters. The letters on both sides are always full of affection and sympathy, and are written in that spirit of confidence which arises from a deep sense of the value and necessity of mutual support in the troubles of life. And with his active and varied employments and his numerous family there was no lack of troubles. They were both of them simple-minded,
58 GEORGE BIDDELL AIRY.
sensible, and practical people, and were very grateful for such comforts and advantages as they were able to command, but for nothing in comparison with their deep respect and affec- tion for one another.
Both by natural ability and ' education she was well qualified to enter into the pursuits of her husband, and in many cases to assist him. She always welcomed her hus- band's friends, and by her skill and attractive courtesy kept them well together. She was an admirable letter-writer, and in the midst of her numerous domestic distractions always found time for the duties of correspondence. In conversation she was very attractive, not so much from the wit or brilliancy of her remarks as from the brightness and interest with which she entered into the topics under discussion, and from the unfailing grace and courtesy with which she attended to the views of others. This was especially recognized by the foreign astronomers and men of science who from time to time stayed as guests at the Observatory and to whom she acted as hostess. Although she was not an accomplished linguist yet she was well able to express herself in French and German, and her natural good sense and kindliness placed her guests at their ease, and made them feel them- selves (as indeed they were) welcomed and at home.
Her father, the Rev. Richard Smith, was a man of most cultivated mind, and of the highest principles, with a keen enjoyment of good society, which the confidence and friend- ship of his patron the Duke of Devonshire amply secured to him, both at Chatsworth and in London. He had a deep attachment to his Alma Mater of Cambridge, and though not himself a mathematician he had a great respect for the science of mathematics and for eminent mathematicians. During the long courtship already related Mr Smith con- ceived the highest respect for Airy's character, as well as for his great repute and attainments, and expressed his lively satisfaction at his daughter's marriage. Thus on January 2Oth, 1830, he wrote to his intended son-in-law as follows : " I have
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 59
little else to say to you than that I continue with heartfelt satisfaction to reflect on the important change about to take place in my dear daughter's situation. A father must not allow himself to dilate on such a subject : of course I feel confident that you will have no reason to repent the irre- vocable step you have taken, but from the manner in which Richarda has been brought up, you will find such a helpmate in her as a man of sense and affection would wish to have, and that she is well prepared to meet the duties and trials (for such must be met with) of domestic life with a firm and cultivated mind, and the warm feelings of a kind heart. Her habits are such as by no means to lead her to expensive wishes, nor will you I trust ever find it necessary to neglect those studies and pursuits upon which your reputation and subsistence are chiefly founded, to seek for idle amusements for your companion. I must indulge no further in speaking of her, and have only at present to add that I commit in full confidence into your hands the guardianship of my daughter's happiness." And on April 5th, 1830, shortly after their marriage, he wrote to his daughter thus : " If thinking of you could supply your place amongst us you would have been with us unceasingly, for we have all of us made you the principal object of our thoughts and our talk since you left us, and I travelled with you all your journey to your present delightful home. We had all but one feeling of the purest pleasure in the prospect of the true domestic comfort to which we fully believe you to be now gone, and we rejoice that all your endearing qualities will now be employed to promote the happiness of one whom we think so worthy of them as your dear husband, who has left us in the best opinion of his good heart, as well as his enlightened and sound understanding. His late stay with us has endeared him to us all. Never did man enter into the married state from more honourable motives, or from a heart more truly seeking the genuine happiness of that state than Mr Airy, and he will, I trust, find his reward in you from all that a
60 GEORGE BIDDELL AIRY.
good wife can render to the best of husbands, and his hap- piness be reflected on yourself." It would be difficult to find letters of more genuine feeling and satisfaction, or more eloquently expressed, than these.
The narrative of the Autobiography will now be resumed.
" I had been disappointed two years before of an expe- dition to Derbyshire. I had wished still to make it, and my brother wished to go : and we determined to make it this year (1824). We were prepared with walking dresses and knapsacks. I had well considered every detail of our route, and was well provided with letters of introduction, including one to the Rev. R. Smith of Edensor. On June 29th we started by coach to Newmarket and walked through the Fens by Ramsay to Peterborough. Then by Stamford and Ketton quarries to Leicester and Derby. Here we were recognized by a Mr Calvert, who had seen me take my degree, and he invited us to breakfast, and employed himself in shewing us several manufactories, &c. to which we had been denied access when presenting ourselves unsupported. We then went to Belper with an introduction from Mr Calvert to Jedediah Strutt: saw the great cotton mills, and in the evening walked to Matlock. Up to this time the country of greatest interest was the region of the fens about Ramsay (a most remarkable district), but now began beauty of scenery. On July pth we walked by Rowsley and Haddon Hall over the hills to Edensor, where we stayed till the I2th with Mr Smith. We next visited Hathersage, Castleton, and Marple (where I wished to see the canal aqueduct), and went by coach to Manchester, and afterwards to Liverpool. Here Dr Traill recommended us to -see the Pontycyssylte Aqueduct, and we went by Chester and -Wrexham to Rhuabon, saw the magnificent work, and proceeded to Llangollen. Thence by Chester and Northwich (where we descended a salt-mine) to Macclesfield. Then to the Ecton mine (of which we saw but little) through Dovedale to
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 6 1
Ashbourn, and by coach to Derby. On July 24th to Birmingham, where we found Mr Guest, lodged in his house, and were joined by my pupil Guest. Here we were fully employed in visiting the manufactures, and then went into the iron country, where I descended a pit in the Staffordshire Main. Thence by coach to Cambridge, where I stopped to prepare for the Fellowship Examination.
" I had two pupils in this portion of the Long Vacation, Turner and Dobbs. On August 2nd my writing of Latin began regularly as before. My principal mathematics on the quires are Optics. On August 25th I made experiments on my left eye, with good measures, and on Aug. 26th ordered a cylindrical lens of Peters, a silversmith in the town, which I believe was never made. Subsequently, while at Playford, I ordered cylindrical lenses of an artist named Fuller, living at Ipswich, and these were completed in November, 1824.
" My letter to the Examiners, announcing my intention of sitting for Fellowship (which like all other such documents is preserved on my quires) was delivered on Sept. 2ist. The Examination took place on Sept. 22nd and the two following days. On Oct. 1st, 1824, at the usual hour of the morning, I was elected Fellow. There were elected at the same time T. B. Macaulay (afterwards Lord Macaulay), who was a year senior to me in College, and I think Field of my own year. I drew up my letter of acknowledgment to the Electors. On Oct. 2nd at 9 in the morning I was admitted Fellow with the usual ceremonies, and at 10 I called on the Electors with my letter of acknowledgment. I immediately journeyed to Derbyshire, paid a visit at Edensor, and returned by Sheffield.
"On Oct. nth (it having been understood with Mr Higman that my engagement as Assistant Mathematical Tutor stood) the Master sent for me to appoint me and to say what was expected as duty of the office. He held out to me the prospect of ultimately succeeding to the Tutorship, and I told him that I hoped to be out of College before that time.
62 GEORGE BIDDELL AIRY.
" About this time the ' Athenaeum,' a club of a scientific character, was established in London, and I was nominated on it, but I declined . (Oct. I4th). In this year (1824) I commenced account with a banker by placing £110 in the hands of Messrs Mortlock and Co". On Oct. i6th I walked to Bury, and after a single day's stay there returned to Cambridge.
"On Oct. 23rd, 1824, 1 began my lectures as Mathematical Assistant Tutor. I lectured the Senior Sophs and Junior Sophs on Higman's side. The number of Senior Sophs was 21. Besides this I took part in the 'Examinations of the Questionists,' a series of exercises for those who were to take the Bachelor's degree in the next January. I examined in Mechanics, Newton, and Optics. I had also as private pupils Turner, Dobbs, and Cooper. I now ceased from the exercise which I had followed with such regularity for five years, namely that of daily writing Latin. In its stead I engaged a French Master (Goussel) with whom I studied French with reasonable assiduity for the three terms to June, 1825.
" Among mathematical investigations I find : Theory of the Moon's brightness, Motion of a body in an ellipse round two centres of force, Various differential equations, Numerical computation of sin TT from series, Numerical computation of sines of various arcs to 18 decimals, Curvature of surfaces in various directions, Generating functions, Problem of sound. I began in the winter a Latin Essay as competing for the Middle Bachelors' Prize, but did not proceed with it. I afterwards wished that I had followed it up : but my time was fully occupied.
"On Jan. 28th, 1825, I started for Edensor, where I paid a visit, and returned on Feb. 2nd. On Feb. 4th I wrote to Mr Clarkson, asking his advice about a profession or mode of life (the cares of life were now beginning to press me heavily, and continued to do so for several years). He re- plied very kindly, but his answer amounted to nothing.
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 63
About the same time I had some conversation of the same kind with Mr Peacock, which was equally fruitless.
" On Feb. 4th I have investigations of the density of light near a caustic (on the theory of emissions). On Feb. 5th I finished a Paper about the defect in my eye, which was com- municated to the Cambridge Philosophical Society on Feb. 2 1 st. Mr Peacock or Mr Whewell had some time previously applied to me to write a Paper on Trigonometry for the Encyclopaedia Metropolitana, and I had been collecting some materials (especially in regard to its history) at every visit to London, where I read sometimes at the British Museum: also in the Cambridge libraries. I began this Paper (roughly) on Feb. 8th, and finished it on Mar. 3rd. The history of which I speak, by some odd management of the Editors of the Encyclopaedia, was never published. The MS. is now amongst the MSS. of the Royal Observatory, Greenwich. Other subjects on my quires are : Theory of musical con- cords, many things relating to trigonometry and trigono- metrical tables, achromatic eye-pieces, equation to the surface bounding the rays that enter my left eye, experiments on percussion. Also notes on Cumberland and Wales (I had already proposed to myself to take a party of pupils in the Long Vacation to Keswick), and notes on history and geology.
"I had been in correspondence with Dr Malkin (master of Bury School), who on Feb. 8th sent a certificate for my brother William, whom I entered at Trinity on Peacock's side. On Mar. 25th I changed my rooms, quitting those on the ground-floor east side of Queen Mary's Gate for first- floor rooms in Neville's Court, south side, the easternmost rooms. In this term my lectures lasted from Apr. i8th to May I4th. Apparently I had only the Senior Sophs, 19 in number, and the same four pupils (Turner, Dobbs, Cooper, Hovenden) as in the preceding term. The only scientific subjects on which I find notes are, a Paper on the forms of the Teeth of Wheels, communicated to the Philosophical
64 GEORGE BIDDELL AIRY.
Society on May 2nd ; some notes about Musical Concords, and some examination of a strange piece of Iceland Spar. On Apr. 29th I was elected to the Northern Institution (of Inverness) ; the first compliment that I received from an extraneous body.
"On May I4th I have a most careful examination of my money accounts, to see whether I can make an expedition with my sister into Wales. My sister came to Cambridge, and on Monday, May 23rd, 1825, we started for Wales, equipped in the lightest way for a walking expedition. We went by Birmingham to Shrewsbury : then to the Pontycys- sylte Aqueduct and by various places to Bala, and thence by Llanrwst to Conway. Here the suspension bridge was under construction : the mole was made and the piers, but nothing else. Then on to Bangor, where nine chains of the suspen- sion bridge were in place, and so to Holyhead. Then by Carnarvon to Bethgelert, ascending Snowdon by the way, and in succession by Festiniog, Dolgelly, and Aberystwyth to Hereford (the first time that I had visited it since my father left it). From thence we went by coach to London, and I went on to Cambridge on the 23rd of June.
" I had arranged to take a party of pupils to Keswick, and to take my brother there. Mr Clarkson had provided me with introductions to Mr Southey and Mr Wordsworth. On Wednesday, June 29th, 1825, we started, and went by Leicester, Sheffield, Leeds, and Kendal, to Keswick, calling at Edensor on the way. My pupils were Cleasby, Marshman, Clinton, Wigram, Tottenham, and M. Smith. At Keswick I passed three months very happily. I saw Mr Southey's family frequently, and Mr Wordsworth's occasionally. By continual excursions in the neighbourhood, and by a few excursions to places as distant as Bowness, Calder Bridge, &c. (always climbing the intermediate mountains), I became well acquainted with almost the whole of that beautiful country, excepting some of the S. W. dales. A geological hammer and a mountain barometer were very interesting
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 65
companions. I had plenty of work with my pupils : I worked a little Lunar Theory, a little of Laplace's Equations, some- thing of the Figure of the Earth, and I wrote out very care- fully my Trigonometry for the Encyclopaedia Metropolitana. I read a little of Machiavelli, and various books which I bor- rowed of Mr Southey. On Friday, Sept 3Oth, my brother and I left for Kendal, and after a stay of a few days at Edensor, arrived at Cambridge on Oct. nth.
"On Oct. 2 1st my Lectures to the Junior Sophs began, 39 names, lasting to Dec. I3th. Those to the Senior Sophs, 16 names, Oct 2Qth to Dec. loth. I also examined Ques- tionists as last year. I have notes about a Paper on the con- nection of impact and pressure, read at the Philosophical Society on Nov. I4th, but not printed, dipping-needle prob- lems, curve described round three centres of force, barometer observations, theory of the Figure of the Earth with variable density, and effect on the Moon, correction to the Madras pendulum, wedge with friction, spots seen in my eyes, density of rays near a caustic. In this term I accomplished the pre- paration of a volume of Mathematical Tracts on subjects which, either from their absolute deficiency in the University or from the unreadable form in which they had been pre- sented, appeared to be wanted. The subjects of my Tracts were, Lunar Theory (begun Oct. 26th, finished Nov. 1st), Figure of the Earth (ist part finished Nov. i8th), Precession and Nutation (my old MS. put in order), and the Calculus of Variations. I applied, as is frequently done, to the Syndicate of the University Press for assistance in publishing the work ; and they agreed to give me paper and printing for 500 copies. This notice was received from Professor Turton on Nov. 29th, 1825. It was probably also in this year that I drew up an imperfect 'Review' of Coddington's Optics, a work which deserved severe censure : my review was never finished.
" In the Long Vacation at Keswick I had six pupils at £42 each. In the October term I had Marshman and Ogilby at £105 for three terms, and Dobbs at £75 for three A. B. 5
66 GEORGE BIDDELL AIRY.
terms. I had, at Mr Peacock's suggestion, raised my rate from 60 to 100 guineas for three terms: this prevented some from applying to me, and induced some to withdraw who had been connected with me : but it .did me no real hurt, for engrossment by pupils is the w6rst of all things that can happen to a man who hopes to distinguish himself. On Dec. 1 7th I went to Bury, and returned to Cambridge on Jan. 30th, 1826.
"I have the attendance-bills of my Lectures to Senior Sophs (16) from Feb. 3rd to Feb. 23rd, and to Freshmen (40) from Feb. 2;th to Mar. 15. It would appear that I gave but one college-lecture per day (my belief was that I always had two). The tutor's stipend per term was £50. On my quires I find, Investigations for the ellipticity of a heterogeneous
spheroid when the density is expressed by - — — (the remark- able properties of which I believe I discovered entirely myself, although they had been discovered by other persons), Theo- retical Numbers for precession, nutation, &c., some investiga- tions using Laplace's Y, hard work on the Figure of the Earth to the 2nd order, ' Woodhouse's remaining apparatus/ Notes about Lambton's and Kater's errors, Depolarization, Notes of Papers on depolarization in the Phil. Trans., Mag- netic Investigations for Lieut. Foster, Isochronous Oscilla- tions in a resisting medium, Observations on a strange piece of Iceland Spar. On Mar. /th forwarded Preface and Title Page for my Mathematical Tracts.
" Some time in this term I began to think of the possi- bility of observing the diminution of gravity in a deep mine, and communicated with Whewell, who was disposed to join in experiments. My first notion was simply to try the rate of a clock, and the Ecton mine was first thought of. I made enquiries about the Ecton mine through Mr Smith (of Eden- sor), and visited the mine, but in the meantime Whewell had made enquiries in London and found (principally from Dr Paris) that the mine of Dolcoath near Camborne in Cornwall
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 67
would be a better place for the experiment. Dr Paris wrote to me repeatedly, and ultimately we resolved on trying it there. In my papers on Mar. 2ist are various investigations about attractions in both mines. On Apr. 3rd I went to London, principally to arrange about Dolcoath, and during April and May I was engaged in correspondence with Sir H. Davy (President of the Royal Society), Mr Herschel, and Dr Young (Secretary of the Board of Longitude) about the loan of instruments and pendulums. On Apr. 23rd I was prac- tising pendulum-observations (by coincidence); and about this time repeatedly practised transits with a small instru- ment lent by Mr Sheepshanks (with whom my acquaintance must have begun no long time before) which was erected under a tent in the Fellows' Walks. On my quires I find various schemes for graduating thermometers for pendulum experiments.
" I find also Notes of examination of my brother William, who had come to College last October ; and a great deal of correspondence with my mother and sister and Mr Case, a lawyer, about a troublesome business with Mr Cropley, an old friend of G. Biddell, to whom my father had lent ^"500 and whose affairs were in Chancery.
" My lectures in this term were to the Junior Sophs from Apr. loth to May I3th : they were six in number and not very regular. On Apr. 28th I sent to Mawman the copy of my Trigonometry for the Encyclopaedia Metropolitana, for which I received £42. I received notice from the Press Syn- dicate that the price of my Mathematical Tracts was fixed at 6s. 6d. : I sold the edition to Deighton for £70, and it was immediately published. About this time I have letters from Mr Herschel and Sir H. Davy about a Paper to be presented to the Royal Society — I suppose about the Figure of the Earth to the 2nd order of ellipticity, which was read to the Royal Society on June I5th.
"On Saturday, May I3th, 1826, I went to London on the way to Dolcoath, and received four chronometers from the
5—2
68 GEORGE BIDDELL AIRY.
Royal Observatory, Greenwich. I travelled by Devonport and Falmouth to Camborne, where I arrived on May 2Oth and dined at the count-house dinner at the mine. I was accompanied by Ibbotson, who was engaged as a pupil, and intended for an engineer. On May 24th Whewell arrived, and we took a pendulum and clock down, and on the 3<Dth commenced the observation of coincidences in earnest. This work, with the changing of the pendulums, and sundry short expeditions, occupied nearly three weeks. We had continued the computation of our observations at every possible interval. It is to be understood that we had one detached pendulum swinging in front of a clock pendulum above, and another similarly mounted below ; and that the clocks were compared by chronometers compared above, carried down and com- pared, compared before leaving, and brought up and com- pared. The upper and lower pendulums had been inter- changed. It was found now that the reliance on the steadi- ness of the chronometers was too great ; and a new method was devised, in which for each series the chronometers should make four journeys and have four comparisons above and two below. This arrangement commenced on the ipth June and continued till the 26th. On the 26th we packed the lower instruments, intending to compare the pendulum directly with the upper one, and sent them up the shaft: when an inexplicable occurrence stopped all proceedings. The basket containing all the important instruments was brought up to the surface (in my presence) on fire ; some of the instruments had fallen out with their cases burning. Whether a super- stitious miner had intentionally fired it, or whether the snuff of a candle had been thrown into it, is not known. Our labour was now rendered useless. On the 28th I packed up what remained of instruments, left for Truro, and arrived at Bury on July 1st. During our stay in Cornwall I had attended a 'ticketing' or sale of ore at Camborne, and we had made expeditions to the N. W. Coast, to Portreath and Illogan, to Marazion and St Michael's Mount, and to Pen-
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 69
zance and the Land's End. On July 3rd I saw Mr Cropley in Bury gaol, and went to Cambridge. On the 4th I was admitted A.M., and on the 5th was admitted Major Fellow.
" I had engaged with four pupils to go to Orleans in this Long Vacation : my brother William was also to go. One of my pupils, Dobbs, did not join : the other three were Tinkler, Ogilby, and Ibbotson. We left London on July 9th, and travelled by Brighton, Dieppe, Rouen, and Paris to Orleans. At Paris I saw Bouvard, Pouillet, Laplace and Arago. I had introductions from Mr Peacock, Mr South, Mr Herschel, Dr Young ; and from Professor Sedgwick to an English resi- dent, Mr Underwood. On the I9th I was established in the house of M. Lagarde, Protestant Minister. Here I received my pupils. On the 28th I commenced Italian with an Italian master : perhaps I might have done more prudently in adher- ing to French, for I made no great progress. On Aug. 2nd I saw a murderer guillotined in the Place Martroi. The principal investigations on my quires are — Investigations about pendulums, Calculus of Variations, Notes for the Figure of the Earth (Encyc. Metrop.) and commencement of the article, steam-engine machinery, &c. I picked up various French ballads, read various books, got copies of the Marseillaise (this I was obliged to obtain rather secretly, as the legitimist power under Charles X. was then at its height) and other music, and particulars of farm wages for Whewell and R. Jones. The summer was intensely hot, and I believe that the heat and the work in Dolcoath had weak- ened me a good deal. The family was the old clergyman, his wife, his daughter, and finally his son. We lived together very amicably. My brother lodged in a Cafe in the Place Martroi ; the others in different families. I left Orleans on Sept. 30th for Paris. Here I attended the Institut, and was present at one of Ampere's Lectures. I arrived at Cambridge on Oct. 1 4th.
"On Oct. i6th Whewell mentioned to me that the Lu- casian Professorship would be immediately vacated by
70 GEORGE BIDDELL AIRY.
Turton, and encouraged me to compete for it. Shortly after- wards Mr Higman mentioned the Professorship, and Joshua King (of Queens') spoke on the restriction which prevented College tutors or Assistant tutors from holding the office. About this time Mr Peacock rendered me a very important service. As the emolument of the Lucasian Professorship was only £99, and that of the Assistant Tutorship £150, I had determined to withdraw from the candidature. But Mr Peacock represented to me the advantage of position which would be gained by obtaining the Professorship (which I then instantly saw), and I continued to be a candidate. I wrote letters to the Heads of Colleges (the electors) and canvassed them personally. Only Dr Davy, the Master of Caius College, at once promised me his vote. Dr French, Master of Jesus College, was a candidate ; and several of the Heads had promised him their votes. Mr Babbage, the third candi- date, threatened legal proceedings, and Dr French withdrew. The course was now open for Mr Babbage and me.
"In the meetings of the Philosophical Society a new mode of proceeding was introduced this term. To enliven the meetings, private members were requested to give oral lectures. Mine was the second, I think, and I took for subject The Machinery of the Steam Engines in the Cornish mines, and especially of the Pumping Engines and Pumps. It made an excellent lecture : the subjects were at that time undescribed in books, and unknown to engineers in general out of Cornwall.
"My College lectures seem to have been, Oct. 2ist to Dec. I4th to 31 Junior Sophs, Dec. 4th to I2th to 12 Senior Sophs. I assisted at the examinations of the Questionists. I had no private pupils. On Nov. 26th I communicated to the Cambridge Philosophical Society a Paper on the Theory of Pendulums, Balances, and Escapements : and I find appli- cations of Babbage's symbolism to an escapement which I proposed. I have various investigations about the Earth, supposed to project at middle latitudes above the elliptical
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 71
form. In November an account of the Dolcoath failure (by Whewell) was given to the Royal Society.
"At length on Dec. 7th, 1826, the election to the Lucasian Professorship took place: I was elected (I think unanimously) and admitted. I believe that this gave great satisfaction to the University in general. My uncle, Arthur Biddell, was in Cambridge on that evening, and was the first of my friends who heard of it. On the same page of my quires on which this is mentioned, there is a great list of apparatus to be con- structed for Lucasian Lectures, notes of experiments with Atwood's Machine, &c. In December, correspondence with Dollond about prisms. I immediately issued a printed notice that I would give professorial lectures in the next Term.
"On Dec. I3th I have a letter from Mr Smith informing me of the dangerous illness (fever) which had attacked nearly every member of his family, Richarda worst of all. On Dec. 23rd I went to Bury. The affairs with Cropley had been settled by the sale of his property under execution, and my father did not lose much of his debt. But he had declined much in body and mind, and now had strange hallucinations.
"The commencement of 1827 found me in a better posi- tion (not in money but in prospects) than I had before stood in: yet it was far from satisfactory. I had resigned my Assistant Tutorship of £150 per annum together with the prospect of succeeding to a Tutorship, and gained only the Lucasian Professorship of £99 per annum. I had a great aversion to entering the Church : and my lay fellowship would expire in 7 years. My prospects in the law or other professions might have been good if I could have waited : but then I must have been in a state of starvation probably for many years, and marriage would have been out of the question : I much preferred a moderate income in no long time, and I am sure that in this I judged rightly for my happi- ness. I had now in some measure taken science as my line (though not irrevocably), and I thought it best to work it well, for a time at least, and wait for accidents.
72 GEORGE BIDDELL AIRY.
" The acceptance of the Lucasian Professorship prevented me from being pressed by Sedgwick (who was Proctor this year) to take the office of moderator : which was a great relief to me. As Lucasian Professor I was ipso facto Member of the Board of Longittfde. A stipend of £100 a year was attached to this, on condition of attending four meetings : but I had good reason (from intimations by South and other persons in London) for believing that this would not last long. The fortnightly notices of the meetings of the Board were given on Jan. i8th, Mar. 22nd, May 24th and Oct. i8th.
"On Jan. 2nd, 1827, I came from London to Bury. I found my father in a very declining state (the painful rheumatism of some years had changed to ulcerations of the legs, and he was otherwise helpless and had distressing hal- lucinations). On Jan. 8th I walked to Cambridge. At both places I was occupied in preparations for the Smith's Prize Examination and for lectures (for the latter I obtained at Bury gaol some numerical results about tread-mills).
" Of the Smith's Prize I was officially an Examiner : and I determined to begin with — what had never been done before — making the examination public, by printing the papers of questions. The Prize is the highest Mathematical honour in the University : the competitors are incepting Bachelors of Arts after the examination for that Degree. My day of examination (apparently) was Jan. 2ist. The candidates were Turner, Cankrein, Cleasby, and Mr Gordon. The first three had been my private pupils : Mr Gordon was a Fellow-commoner of St Peter's College, and had just passed the B.A. examination as Senior Wrangler, Turner being second. My situation as Examiner was rather a delicate one, and the more so as, when I came to examine the papers of answers, Turner appeared distinctly the first. Late at night I carried the papers to Whewell's rooms, and he on inspection agreed with me. The other examiners (Professors Lax and Woodhouse, Lowndean and Plumian Professors)
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 73
generally supported me : and Turner had the honour of First Smith's Prize.
" On Jan. 3Oth my mother wrote, asking if I could see Cropley in London, where he was imprisoned for contempt of Chancery. I attended the meeting of the Board of Longitude on Feb. ist, and afterwards visited Cropley in the Fleet Prison. He died there, some time later. It was by the sale of his effects under execution that my father's debt was paid.
"On Feb. i$th I communicated to the Royal Society a Paper on the correction of the Solar Tables from South's observations. I believe that I had alluded to this at the February meeting of the Board of Longitude, and that in consequence Mr Pond, the Astronomer Royal, had been re- quested to prepare the errors of the Sun's place from the Greenwich observations : which were supplied some months later. With the exception of South's Solar Errors, and some investigations about dipping-needles, I do not find anything going on but matters connected with my ap- proaching lectures. There are bridges, trusses, and other mechanical matters, theoretical and practical, without end. Several tradesmen in Cambridge and London were well em- ployed. On Feb. I3th I have a letter from Cubitt about groins : I remember studying those of the Custom-house and other places. On Feb. 2Oth my Syllabus of Lectures was finished : this in subsequent years was greatly improved. I applied to the Royal Society for the loan of Huyghens's object-glass, but they declined to lend it. About this time I find observations of the spectrum of Sirius.
" There had been no lectures on Experimental Philosophy (Mechanics, Hydrostatics, Optics) for many years. The University in general, I believe, looked with great satisfac- tion to my vigorous beginning : still there was considerable difficulty about it. There was no understood term for the Lectures : no understood hour of the day : no understood lecture room. I began this year in the Lent Term, but in
74 GEORGE BIDDELL AIRY.
all subsequent years I took the Easter Term, mainly for the chance of sunlight for the optical experiments, which I soon made important. I could get no room but a private or retiring room (not a regular lecture room) in the buildings at the old Botanic Garden : in following years I had the room under the University Library. The Lectures commenced on some day in February 1827: I think that the number who attended them was about 64. I remember very well that the matter which I had prepared as an Introductory Lecture did not last above half the time that I had expected, but I managed very well to fill up the hour. On another occasion I was so ill-prepared that I had contemplated giving notice that I was unable to complete the hour's lecture, but I saw in the front row some strangers, introduced by some of my regular attendants, very busy in taking notes, and as it was evident that a break-down now would not do, I silently exerted myself to think of something, and made a very good lecture.
"On Mar. ist, as official examiner, I received notices from 14 candidates for Bell's Scholarships, and prepared my Paper of questions. I do not remember my day of examina- tion ; but I had all the answers to all the examiners' ques- tions in my hands, when on Mar. 2/th I received notice that my father had died the preceding evening. This stopped my Lectures : they were concluded in the next term. I think that I had only Mechanics and imperfect Optics this term, no Hydrostatics; and that the resumed Lectures were princi- pally Optical. They terminated about May I4th.
" With my brother I at once went to Bury to attend my father's funeral. He was buried on Mar. 3ist, 1827, in the churchyard of Little Whelnetham, on the north side of the church. Shortly afterwards I went to London, and on Apr. 5th I attended a meeting of the Board of Longitude, at which Herschel produced a Paper regarding improvements of the Nautical Almanac. Herschel and I were in fact the leaders of the reforming party in the Board of Longitude : Dr Young
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 75
the Secretary resisted change as much as possible. After the meeting I went to Cambridge. I find then calculations of achromatic eye-pieces for a very nice model with silk threads of various colours which I made with my own hands for my optical lectures.
" On Apr. 7th Herschel wrote to me that the Professor- ship held by Dr Brinkley (then appointed Bishop of Cloyne) at Dublin would be vacant, and recommended it to my notice, and sent me some introductions. I reached Dublin on Apr. 1 5th, where I was received with great kindness by Dr Brinkley and Dr MacDonnell (afterwards Provost). I there met the then Provost Dr Bartholomew Lloyd, Dr Lardner, Mr Hamilton (afterwards Sir W. R. Hamilton) and others. In a few days I found that they greatly desired to appoint Hamilton if possible (they did in fact overcome some difficulties and appoint him in a few months), and that they would not make such an augmentation as would induce me to offer myself as a candidate, and I withdrew. I have always remembered with gratitude Dr MacDonnell's conduct, in carefully putting me on a fair footing in this matter. I returned by Holyhead, and arrived at Birmingham on Apr. 23rd. While waiting there and looking over some papers relating to the spherical aberration of eye-pieces, in which I had been stopped some time by a geometrical difficulty, I did in the coffee-room of a hotel overcome the difficulty; and this was the foundation of a capital paper on the Spherical Aberration of Eye-pieces. This paper was afterwards pre- sented to the Cambridge Philosophical Society.
" About this time a circumstance occurred of a disagree- able nature, which however did not much disconcert me. Mr Ivory, who had a good many years before made himself favourably known as a mathematician, especially by his acquaintance with Laplace's peculiar analysis, had adopted (as not unfrequently happens) some singular hydrostatical theories. In my last Paper on the Figure of the Earth, I had said that I could not receive one of his equations. In
76 GEORGE BIDDELL AIRY.
the Philosophical Magazine of May he attacked me for this with great heat. On May 8th I wrote an answer, and I think it soon became known that I was not to be attacked with impunity.
" Long before this time there1 had been some proposal about an excursion to the Lake District with my sister, and I now arranged to carry it out. On May 23rd I went to Bury and on to Playford : while there I sketched the Cum- berland excursion. On June 5th I went to London, I believe to the Visitation of the Greenwich Observatory to which I was invited. I also attended the meeting of the Board of Longitude. I think it was here that Pond's Errors of the Sun's place in the Nautical Almanac from Greenwich Obser- vations were produced. On June /th I went by coach to Rugby, where I met my sister, and we travelled to Edensor. We made a number of excursions in Derbyshire, and then passed on by Penrith to Keswick, where we arrived on June 22nd. From Keswick we made many excursions in the Lake District, visited Mr Sou they and Mr Wordsworth, descended a coal mine at Whitehaven, and returned to Edensor by the way of Ambleside, Kendal, and Manchester. With sundry excursions in Derbyshire our trip ended, and we returned to Cambridge on the 2ist July.
" During this Long Vacation I had one private pupil, Crawford, the only pupil this year, and the last that I ever had. At this time there is on my papers an infinity of opti- cal investigations : also a plan of an eye-piece with a concave lens to destroy certain aberrations. On Aug. 2Oth I went to Woodford to see Meosrs Gilbert's optical works. From Aug. 1 3th I had been preparing for the discussion of the Green- wich Solar Errors, and I had a man at work in my rooms, engaged on the calculation of the Errors. I wrote to Bouvard at Paris for observations of the sun, but he recommended me to wait for the Tables which Bessel was preparing. I was busy too about my Lectures : on Sept. 2Qth I have a set of plans of printing presses from Hansard the printer (who in a
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 77
visit to Cambridge had found me making enquiries about them), and I corresponded with Messrs Gilbert about optical constructions, and with W. and S. Jones, Eastons, and others about pumps, hydraulic rams, &c. On Sept. 25th occurred a very magnificent Aurora Borealis.
" I do not find when the investigation of Corrections of Solar Elements was finished, or when my Extracts from Burckhardt, Connaissance des Temps 1816, were made. But these led me to suspect an unknown inequality in the Sun's motion. On Sept. 27th and 28th I find the first suspicions of an inequality depending on 8 x mean longitude of Venus — 13 x mean longitude of Earth. The thing appeared so promising that I commenced the investigation of the pertur- bation related to this term, and continued it (a very laborious work) as fast as I was able, though with various interruptions, which in fact were necessary to keep up my spirits. On Oct. 3<Dth I went to London for the Board of Longitude meeting. Here I exhibited the results of my Sun investiga- tions, and urged the correction of the elements used in the Nautical Almanac. Dr Young objected, and proposed that Bouvard should be consulted. Professor Woodhouse, the Plumian Professor, was present, and behaved so captiously that some members met afterwards to consider how order could be maintained. I believe it was during this visit to London that I took measures of Hammersmith Suspension Bridge for an intended Lecture-model. Frequently, but not always, when in London, I resided at the house of Mr Sheep- shanks and his sister Miss Sheepshanks, 30 Woburn Place. My quires, at this time, abound with suggestions for lectures and examinations.
" On some day about the end of November or beginning of December 1827, when I was walking with Mr Peacock near the outside gate of the Trinity Walks, on some mention of Woodhouse, the Plumian Professor, Mr Peacock said that he was never likely to rise into activity again (or using some expression importing mortal illness). Instantly there had
78 GEORGE BIDDELL AIRY.
passed through my mind the certainty of my succeeding him, the good position in which I stood towards the University, the probability of that position being improved by improved lectures, &c., &c., and J>y increased reputation from the matters in which I was now engaged, the power of thus commanding an increase of income. I should then have, independent of my Fellowship, some competent, income, and a house over my head. I was quite aware that some time might elapse, but now for the first time I saw my way clearly. The care of the Observatory had been for two or three years attached to the Plumian Professorship. A Grace was imme- diately prepared, entrusting the temporary care of the Obser- vatory to Dr French, to me, Mr Catton, Mr Sheepshanks, and Mr King (afterwards Master of Queens' College). On Dec. 6th I have a note from Mr King about going to the Observatory.
" On Dec. 6th my Paper on corrections of the elements of the Solar Tables was presented to the Royal Society. On Dec. Qth, at I h. 4 m. a.m. (Sunday morning), I arrived at the result of my calculations of the new inequality. I had gone through some fluctuations of feeling. Usually the important part of an inequality of this kind depends entirely on the eccentricities of the orbits, but it so happened that from the positions of the axes of the orbits, &c., these terms very nearly destroyed each other. After this came the considera- tion of inclinations of orbits ; and here were sensible terms which were not destroyed. Finally I arrived at the result that the inequality would be about 3"; just such a magnitude as was required. I slipped this into Whewell's door. This is, to the time of writing (1853), the last improvement of any importance in the Solar Theory. Some little remaining work went on to Dec. I4th, and then, being thoroughly tired, I laid by the work for revision at some future time. I however added a Postscript to my Royal Society Paper on Solar Errors, notifying this result.
" On Dec. iQth I went to Bury. While there I heard from
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 79
Whewell that Woodhouse was dead. I returned to Cam- bridge and immediately made known that I was a candidate for the now vacant Plumian Professorship. Of miscellaneous scientific business, I find that on Oct. I3th Professor Barlow of Woolwich prepared a memorial to the Board of Longitude concerning his fluid telescope (which I had seen at Woodford), which was considered on Nov. 1st, and I had some corre- spondence with him in December. In June and August my Trigonometry was printing.
"On Jan. 5th, 1828, I came from London. It seems that I had been speculating truly ' without book ' on perturba- tions of planetary elements, for on Jan. i/th and i8th I wrote a Paper on a supposed error of Laplace, and just at the end I discovered that he was quite right : I folded up the Paper and marked it 'A Lesson/ I set two papers of questions for Smith's Prizes (there being a deficiency of one Examiner, viz. the Plumian Professor).
"Before the beginning of 1828 Whewell and I had deter- mined on repeating the Dolcoath experiments. On Jan. 8th I have a letter from Davies Gilbert (then President of the Royal Society) congratulating me upon the Solar Theory, and alluding to our intended summer's visit to Cornwall. We had somehow applied to the Board of Longitude for pendulums, but Dr Young wished to delay them, having with Capt. Basil Hall concocted a scheme for making Lieut. Foster do all the work : Whewell and I were indignant at this, and no more was said about it. On Jan. 24th Dr Young, in giving notice of the Board of Longitude meeting, informs me that the clocks and pendulums are ready.
" I had made known that I was a candidate for the Plumian Professorship, and nobody thought it worth while to oppose me. One person at least (Earnshaw) had intended to compete, but he called on me to make certain that I was a candidate, and immediately withdrew. I went on in quality of Syndic for the care of the Observatory, ingrafting myself into it. But meantime I told everybody that the salary
80 GEORGE BIDDELL AIRY.
(about ^"300) was not sufficient for me ; and on Jan. 2Oth I drafted a manifesto or application to the University for an increase of salary. The day of election to the Professorship was Feb. 6th. As I was officially (as Lucasian Professor) an elector, I was present, and T explained to the electors that I could not undertake the responsibility of the Observatory without augmentation of income, and that I requested their express sanction to my application to the University for that purpose. They agreed to this generally, and I was elected. I went to London immediately to attend a meeting of the Board of Longitude and returned on Feb. 8th. On Feb. I5th I began my Lectures (which, this year, included Mechanics, Optics, Pneumatics, and Hydrostatics) in the room below the University Library. The number of names was 26. The Lectures terminated on Mar. 22nd.
"On Feb. 25th I received from Mr Pond information on the emoluments at Greenwich Observatory. I drew up a second manifesto, and on Feb. 26th I wrote and signed a formal copy for the Plumian electors. On Feb. 27th I met them at Caius Lodge (the Master, Dr Davy, being Vice- Chancellor). I read my Paper, which was approved, and their sanction was given in the form of a request to the Vice- Chancellor to permit the paper to be printed and circulated. My paper, with this request at the head, was immediately printed, and a copy was sent to every resident M.A. (more than 200 went out in one day). The statement and composi- tion of the paper were generally approved, but the University had never before been taken by storm in such a manner, and there was some commotion about it. I believe that very few persons would have taken the same step. Mr Sheepshanks wrote to me on Mar. 7th, intimating that it was desperate. I had no doubt of success. Whewell told me that some people accused me of bad faith, in omitting allusion to the £100 a year received as Member of the Board of Longitude, and to the profits of Lectures. I wrote him a note, telling him that I had most certain information of the intention to
FROM B.A. DEGREE TO PLUMIAN PROFESSORSHIP. 8 1
dissolve the Board of Longitude (which was done in less than six months), and that by two years' Lectures I had gained £4$ (the expenses being £200, receipts £245). This letter was sent to the complaining people, and no more was said. By the activity of Sheepshanks and the kindness of Dr Davy the business gradually grew into shape, and on Mar. 2ist a Grace passed the Senate for appointing a Syndicate to con- sider of augmentation. Sheepshanks was one of the Syndi- cate, and was understood to represent, in some measure, my interests. The progress of the Syndicate however was by no means a straightforward one. Members of the Senate soon began to remark that before giving anything they ought to know the amount of the University revenue, and another Syndicate was then appointed to enquire and report upon it. It was more than a year before my Syndicate could make their recommendation : however, in fact, I lost nothing by that delay, as I was rising in the estimation of the University. "The Observatory house was furnished, partly from Wood- house's sale, and partly from new furniture. My mother and sister came to live with me there. On Mar. I5th 1828 I began the Observatory Journal ; on Mar. 2/th I slept at the Observatory for the first time, and on Apr. i5th I came to reside there permanently, and gave up my college rooms."
A. B.
CHAPTER IV.
AT CAMBRIDGE OBSERVATORY. FROM HIS TAKING CHARGE OF THE CAMBRIDGE OBSERVATORY TO HIS
RESIDENCE AT GREENWICH OBSERVATORY AS AS-
TRONOMER ROYAL.
FROM MARCH ISTH 1828 TO JAN. IST 1836.
1828
" I attended a meeting of the Board of Longitude on Apr. 3rd. And again on June 4th ; this was the last meeting : Sheepshanks had previously given me private information of the certainty of its dissolution. — On Apr. 4th I visited Mr Herschel at Slough, where one evening I saw Saturn with his 2O-foot telescope, the best view of it that I have ever had. — In June I attended the Greenwich Observatory Visi- tation.— Before my election (as Plumian Professor) there are various schemes on my quires for computation of transit corrections, &c. After Apr. I5th there are corrections for deficient wires, inequality of pivots, &c. And I began a book of proposed regulations for observations. In this are plans for groups of stars for R.A. (the Transit Instrument being the only one finished): order of preference of classes of observations: no reductions to be made after dinner, or on Sunday : no loose papers : observations to be stopped if reductions are two months in arrear: stars selected for parallax. — The reduction of transits begins on Apr. I5th. On May I5th Mr Pond sent me some moon-transits to aid in determining my longitude. — Dr Young, in a letter to me of
AT CAMBRIDGE OBSERVATORY. 83
May /th, enquires whether I will accept a free admission to the Royal Society, which I declined. On May pth I was elected to the Astronomical Society. — Towards the end of the year I observed Encke's Comet: and determined the latitude of the Observatory with Sheepshanks's repeating circle. — On my papers I find a sketch of an Article on the Figure of the Earth for the Encyclopaedia Metropolitana.
"As early as Feb. 23rd I had been in correspondence with T. Jones, the instrument-maker, about pendulums for a repetition of the Dolcoath Experiments. Invitations had been received, and everything was arranged with Whewell. Sheepshanks, my brother, and Mr Jackson of Ipswich (Caius Coll.) were to go. and we were subsequently joined by Sedgwick, and Lodge (Magdalene Coll.). On July 3rd Sheep- shanks and I started by Salisbury, taking Sherborne on our way to look at the church, which had alarmed the people by signs of a crack, and arrived at Camborne on July 8th. On the I4th we set up the pendulums, and at once commenced observations, our plan being, to have no intermission in the pendulum observations, so that as soon as the arc became too small a fresh series was started. On July 2Qth we raised the instruments, and Sheepshanks, who managed much of the upper operations, both astronomical and of pendulums, mounted the pendulums together in his observatory. We went on with our calculations, and on August 8th, on return- ing from a visit to John Williams at Barncoose, we heard that there was a * run ' in Dolcoath, that is a sinking of the whole mass of rock where it had been set free by the mine excava- tions: probably only a few inches, but enough to break the rock much and to stop the pumps. On Aug. loth the calcu- lations of our observations shewed that there was something wrong, and on the I3th I perceived an anomaly in the form of the knife edge of one pendulum, and of its agate planes, and suggested cautions for repeating the observations. We determined at once to repeat them : and as the water was rising in the mine there was no time to be lost. We
6—2
84 GEORGE BIDDELL AIRY.
again sent the instruments down, and made observations on the 1 6th, 1 7th and i8th. On the igth I sent the instruments up, for the water was near our station, and Sedgwick, Whewell, and I went on a geological expedition to the Lizard. On our return we met Sheepshanks and the others, and found the results of the last observations unsatisfactory. The results of comparing the pendulums were discordant, and the knife edge of the faulty pendulum had very sensibly altered. We now gave up observations, with the feeling that our time had been totally lost, mainly through the fault of the maker of the pendulum (T. Jones). On the 28th we made an expedition to Penzance and other places, and arrived at Cambridge on the i/th of September.
" In the course of the work at Dolcoath we made various expeditions as opportunity offered. Thus we walked to Carn Brea and witnessed the wrestling, the common game of the country. On another occasion Sedgwick, Whewell, and I had a capital geological expedition to Trewavas Head to examine granite veins. We visited at Pendarves and Trevince, and made the expedition to the Lizard already referred to, and saw many of the sights in the neighbourhood. After visiting Penzance on the conclusion of our work we saw Cape Cornwall (where Whewell overturned me in a gig), and returned homewards by way of Truro, Plymouth (where we saw the watering-place and breakwater: also the Dock- yard, and descended in one of the working diving-bells), Exeter, Salisbury, and Portsmouth. In returning from Camborne in 1826 I lost the principal of our papers. It was an odd thing that, in going through Exeter on our way to Camborne in 1828, I found them complete at Exeter, identified to the custodian by the dropping out of a letter with my address.
" On my return to Cambridge I was immediately im- mersed in the work of the Observatory. The only instru- ment then mounted at the Observatory was the Transit. I had no Assistant whatever. — A Mr Galbraith of Edinburgh
AT CAMBRIDGE OBSERVATORY. 85
had questioned something in one of my Papers about the Figure of the Earth. I drew up a rather formal answer to it: Whewell saw my draft and drew up a much more pithy one, which I adopted and sent to the Philosophical Magazine. — For comparing our clocks at the upper and lower stations of Dolcoath we had borrowed from the Royal Observatory, Greenwich, six good pocket chronometers : they were still in the care of Mr Sheepshanks. I arranged with him that they should be sent backwards and forwards a few times for determining the longitude of Cambridge Observatory. This was done on Oct. 2ist, 22nd, 23rd: the result was 23S*54, and this has been used to the present time (1853). It evinced an error in the Trigonometrical Survey, the origin of which was found, I think, afterwards (Dr Pearson in a letter of Dec. 1 7th spoke of the mistake of a may-pole for a signal-staff). I drew up a Paper on this, and gave it to the Cambridge Philosophical Society on Nov. 24th. (My only academical Paper this year.) — I had several letters from Dr Young, partly supplying me with calculations that I wanted, partly on reform or extension of the Nautical Almanac (which Dr Young resisted as much as possible). He considered me very unfairly treated in the dissolution of the Board of Longitude : Professor Lax wished me to join in some effort for its restoration, but I declined.
" As my reduction of observations was kept quite close, I now began to think of printing. In regard to the form I determined to adopt a plan totally different from that of any other observations which I had seen. The results were to be the important things : I was desirous of suppressing the separate wires of transits. But upon consulting Herschel and other persons they would not agree to it, and I assented to keeping them. I applied to the Press Syndicate to print the work, and on Nov. loth at the request of T. Musgrave (afterwards Archbishop of York) I sent a specimen of my MS.: on Nov. nth they granted 250 copies, and the printing soon commenced."
86 GEORGE BIDDELL AIRY.
1829
" During a winter holiday at Playford I wrote out some investigations about the 'orbits 0T comets, and on Jan. 23rd 1829 I returned to Cambridge. The Smith's Prize Exami- nation soon followed, in which I set a Paper of questions as usual. On Feb. i8th I made notes on Liesganig's geodetic work at the British Museum.
" I was naturally anxious now about the settlement of my salary and of the Observatory establishment. I do not know when the Syndicate made their Report, but it must have been in the last term of 1828. It recommended that the salary should be annually made up (by Grace) to £500 : that an Assistant should be appointed with the assent of the Vice-Chancellor- and dismissable by the Plumian Professor: and that a Visiting Syndicate should be appointed, partly official and partly of persons to be named every year by Grace. The Grace for adopting this Report was to be offered to the Senate on Feb. 27th. The passing of the Grace was exposed to two considerable perils. First, I found out (just in time) that a Senior Fellow of Trinity (G. A. Browne) was determined to oppose the whole, on ac- count of the insignificant clause regarding dismissal of Assist- ants, which he regarded as tyrannical. I at once undertook that that clause should be rejected. Secondly, by the absurd constitution of the ' Caput ' at Cambridge, a single M. A. had the power of stopping any business whatever, and an M.A. actually came to the Senate House with the intention of throwing out all the Graces on various business that day presented to the Senate. Luckily he mistook the hour, and came at 1 1 instead of 10, and found that all were dispatched. The important parts of the Grace passed without any opposi- tion : but I mustered some friends who negatived that part which had alarmed G. A. Browne, and it was corrected to his satisfaction by a new Grace on Mar. i8th. I was now almost
AT CAMBRIDGE OBSERVATORY. 87
set at rest on one of the great objects of my life: but not quite. I did not regard, and I determined not to regard, the addition to my salary as absolutely certain until a payment had been actually made to me : and I carefully abstained, for the present, from taking any steps based upon it. I found for Assistant at the Observatory an old Lieutenant of the Royal Navy, Mr Baldrey, who came on Mar. 16.
" On May 4th I began lectures : there were 32 names. The Lectures were improving, especially in the optical part. I do not find note of the day of termination. — I do not know the actual day of publication of my first small volume of Cambridge Observations, 1828, and of circulation. The date of the preface is Apr. 2/th 1829. I have letters of approval of it from Davies Gilbert, Rigaud, and Lax. The system which I endeavoured to introduce into printed astronomical observations was partially introduced into this volume, and was steadily improved in subsequent volumes. I think that I am justified, by letters and other remarks, in believing that this introduction of an orderly system of exhibition, not merely of observations but of the steps for bringing them to a practical result — quite a novelty in astronomical publica- tions— had a markedly good effect on European astronomy in general. — In Feb. and March I have letters from Young about the Nautical Almanac : he was unwilling to make any great change, but glad to receive any small assistance. South, who had been keeping up a series of attacks on Young, wrote to me to enquire how I stood in engagements of assistance to Young : I replied that I should assist Young whenever he asked me, and that I disapproved of South's course. — The date of the first visitation of the (Cambridge) Observatory must have been near May nth: I invited South and Baily to my house ; South and I were very near quarrelling about the treatment of Young. — In a few days after Dr Young died : I applied to Lord Melville for the superintendence of the Nautical Almanac: Mr Croker replied that it devolved legally upon the Astronomer Royal, and on May 3<Dth Pond
88 GEORGE BIDDELL AIRY.
wrote to ask my assistance when I could give any. On June 6th I was invited to the Greenwich Visitation, to which I believe I went on the loth.
" I had long desired to see Switzerland, and I wished now to see some of the Continental /Observatories. I was there- fore glad to arrange with Mr Lodge, of Magdalene College (perhaps 10 years senior to myself), to make a little tour. Capt. W. H. Smyth and others gave me introductions. I met Lodge in London, and we started for Calais on July 2;th 1829. We visited a number of towns in Belgium (at Brussels I saw the beginning of the Observatory with Quetelet), and passed by Cologne, Frankfort, Fribourg, and Basle to Zurich. Thus far we had travelled by diligence or posting : we now procured a guide, and travelled generally on foot. From the 1 3th to the 3 ist August we travelled diligently through the well-known mountainous parts of Switzerland and arrived at Geneva on the 3ist August. Here I saw M. Gautier, M. Gambard, and the beginning of the Observatory. Mr Lodge was now compelled to return to Cambridge, and I proceeded alone by Chambery to Turin, where I made the acquaintance of M. Plana and saw the Observatory. I then made a tour through north Italy, looking over the Observatories at Milan, Padua, Bologna, and Florence. At Leghorn I took a passage for Marseille in a xebeque, but after sailing for three days the weather proved very unfavourable, and I landed at Spezia and proceeded by Genoa and the Cornici Road to Marseille. At Marseille I saw M. Gambart and the Observatory, and passed by Avignon, Lyons, and Nevers to Orleans, where I visited my old host M. Legarde. Thence by Paris, Beauvais, and Calais to London and Cambridge, where I arrived on the 30th October. I had started with more than £140 and returned with 2s. 6d. The expedition was in many ways invaluable to me.
" On my return I found various letters from scientific men : some approving of my method for the mass of the Moon : some approving highly of my printed observations,
AT CAMBRIDGE OBSERVATORY. 89
especially D. Gilbert, who informed me that they had pro- duced good effect (I believe at Greenwich), and Herschel. — On Nov. 1 3th I gave the Royal Astronomical Society a Paper about deducing the mass of the Moon from observa- tions of Venus : on Nov. i6th a Paper to the Cambridge Philosophical Society on a correction to the length of a ball- pendulum : and on Dec. I4th a Paper on certain conditions under which perpetual motion is possible. — The engravings for my Figure of the Earth in the Encyclopaedia Metropoli- tana were dispatched at the end of the year. Some of the Paper (perhaps much) was written after my return from the Continent. — I began, but never finished, a Paper on the form of the Earth supposed to be projecting at middle latitudes. In this I refer to the printed Paper which Nicollet gave me at Paris. I believe that the investigations for my Paper in the Encyclopaedia Metropolitana led me to think the supposition unnecessary. — On Nov. 6th I was elected member of the Geological Society.
"On Nov. 1 6th 1829 notice was given of a Grace to authorize payment to me of £157. gs. id., in conformity with the regulations adopted on Feb. 27th, and on Nov. i8th the Grace passed the Senate. On Nov. I9th the Vice-Chancellor wrote me a note enclosing the cheque. On Nov. 23rd (prac- tically the first day on which I could go) I went to London and travelled to Edensor, where I arrived on the 26th. Here I found Richarda Smith, proposed to her, and was accepted. I stayed there a few days, and returned to Cambridge."
1830
"On Jan. 25th 1830 the Smith's Prize Paper was prepared. I was (with my Assistant, Mr Baldrey) vigorously working the Transit Instrument and its reductions, and gradually forming a course of proceeding which has had a good effect on European Astronomy. And I was preparing for my marriage.
GEORGE BIDDELL AIRY.
"On Mar. nth I started with my sister to London, and arrived at Edensor on the afternoon of the I4th. On the 1 7th I started alone for Manchester and Liverpool. Through Mr Mason, a cotton-spinner at Calver, near Edensor, I had become acquainted with Mr Johft Kennedy of Manchester, and I had since 1824 been acquainted with Dr Traill of Liverpool. Amongst other things, I saw the works of the Manchester and Liverpool Railway, then advancing and exciting great interest, and saw George Stephenson and his son. On Mar. 24th I was married to Richarda Smith by her father in Edensor. We stopped at Edensor till Apr. 1st, and then started in chaises by way of Newark and Kettering (where we were in danger of being stopped by the snow), and arrived at Cambridge on Apr. 3rd.
" I was now busy in preparing for lectures, especially the part of the optical lectures which related to the theory of interferences and polarization. I think it was now that my wife drew some of my lecture pictures, exhibiting interference phenomena. My lectures began on Apr. 26th and finished on May 24th. The number of names was 50- They were considered an excellent course of lectures.
" May Qth is the date of my Preface to the 1829 Observa- tions : all was then printed. Apparently I did not go to the Visitation of the Greenwich Observatory this year. — I was at this time pressing Tulley, the optician, about an object-glass for the Mural Circle. — A new edition of my ' Tracts ' was wanted, and I prepared to add a Tract on the Undulatory Theory of Light in its utmost extent. The Syndicate of the University Press intimated through Dr Turton that they could not assist me (regarding the book as a second edition). On July loth I have some negociation about it with Deighton the bookseller. — On May i8th I have a note from Whewell about a number of crystals of plagiedral quartz, in which he was to observe the crystalline indication, and I the optical phenomena. — The Report of the Syndicate for visiting the Observatory is dated June i8th : it is highly laudatory. — The
AT CAMBRIDGE OBSERVATORY. 91
Proctor (Barnard of King's College) requested me to name the Moderator for the next B.A. Examination : I named Mr Challis.
" On June I4th my wife and I went, in company with Pro- fessor and Mrs Henslow, to London and Oxford ; at Oxford we were received in Christchurch College by Dr and Mrs Buckland. My wife and I then went to Bedford to visit Capt. and Mrs Smyth, and returned to Cambridge on the 23rd. On July 5th we went on a visit to my mother and uncle at Playford. While there I took a drive with my uncle into some parts near the valley of the Gipping, in which I thought that the extent of the chalk was inadequately exhibited on Greenough's map, and communicated my re- marks to Buckland.
" I find letters from Dr Robinson and Col. Colby about determining longitudes of certain observatories by fire signals : I proposed chronometers as preferable. Also from Herschel, approving of my second volume of observations : and from F. Baily, disclaiming the origination of the attack on the old Nautical Almanac (with which I suppose I had reproached him). On July 3Oth I received a summons from South to a committee for improving the Nautical Almanac ; and subse- quently a letter from Baily about Schumacher's taking offence at a passage of mine in the Cambridge Observations, on the comparative merits of Ephemerides, which I after- : wards explained to his satisfaction.
" On Aug. 24th my wife and I started for Edensor, and after a short stay there proceeded by Manchester to Cumber- land, where we made many excursions. We returned by Edensor, and reached Cambridge on Oct. 6th, bringing my wife's sister Susanna on a visit. My mother had determined, as soon as my intention of marriage was known to her, to quit the house, although always (even to her death) enter- taining the most friendly feelings and fondness for my wife. It was also judged best by us all that my sister should not reside with us as a settled inhabitant of the house. They
92 GEORGE BIDDELL AIRY.
fixed themselves therefore at Playford in the farm-house of the Luck's Farm, then in the occupation of my uncle Arthur Biddell. On Oct. 2ist I have a letter from my sister saying that they were comfortably settled there.
" In this month of October (principally, I believe) I made some capital Experiments on Quartz, which were treated mathematically in a Paper communicated in the next year to the Cambridge Philosophical Society. In some of these my wife assisted me, and also drew pictures. — On Nov. I5th the Grace for paying me £198. i$s. %d. to make my income up to £500 passed the Senate. — I made three journeys to London to attend committees, one a committee on the Nautical Almanac, and one a Royal Society Committee about two southern observatories. — On Dec. 3ist I have a letter from Maclear (medical practitioner and astronomer at Biggies- wade) about occultations. — In this December I had a quartz object-glass by Cauchaix mounted by Dollond, and presented it to the Observatory. — In this December occurred the alarm from agrarian fires. There was a very large fire at Coton, about a mile from the Observatory. This created the most extraordinary panic that I ever saw. I do not think it is possible, without having witnessed it, to conceive the state of men's minds. The gownsmen were all armed with bludgeons, and put under a rude discipline for a few days."
1831
" On Jan. 4th I went with my wife, first to Miss Sheep- shanks in London, at 30, Woburn Place, and next to the house of my wife's old friend, the Rev. John Courtney, at Sanderstead, near Croydon. I came to London on one day to attend a meeting of the new Board of Visitors of the Greenwich Observatory. Formerly the Board of Visitors consisted of the Council of the Royal Society with persons invited by them (in which capacity I had often attended). But a reforming party, of which South, Babbage, Baily and
AT CAMBRIDGE OBSERVATORY. 93
Beaufort were prominent members, had induced the Admi- ralty to constitute a new Board, of which the Plumian Pro- fessor was a member. Mr Pond, the Astronomer Royal, was in a rather feeble state, and South seemed determined to bear him down : Sheepshanks and I did our best to support him. (I have various letters from Sheepshanks to this pur- pose.)— On Jan. 22nd we returned to Cambridge, and I set an Examination Paper for Smith's Prizes as usual. — On Jan. 30th I have a letter from Herschel about improving the arrangement of Pond's Observations. I believe that much of this zeal arose from the example of the Cambridge Observa- tions.
"On Feb. 2ist my Paper ' On the nature of the light in the two rays of Quartz' was communicated to the Philoso- phical Society : a capital piece of deductive optics. On Mar. 2nd I went to London, I suppose to attend the Board of Visitors (which met frequently, for the proposed reform of Pond's Observations, &c.). As I returned on the outside of the coach there occurred to me a very remarkable deduction from my ideas about the rays of Quartz, which I soon tried with success, and it is printed as an Appendix to the Paper above mentioned. On Mar. 6th my son George Richard was born."
Miscellaneous matters in the first half of this year are as follows :
" Faraday sends me a piece of glass for Amici (he had sent me a piece before). — On Apr. 9th I dispatched the Pre- face of my 1830 Observations: this implies that all was printed. — On Apr. i8th I began my Lectures and finished on May 24th. There were 49 names. A very good series of lectures. — I think it was immediately after this, at the Visita- tion of the Cambridge Observatory, that F. Baily and Lieut. Stratford were present, and that Sheepshanks went to Thar- field on the Royston Downs to fire powder signals to be seen at Biggies wade (by Maclear) and at Bedford (by Capt. Smyth) as well as by us at Cambridge. — On May I4th I received
94 GEORGE BIDDELL AIRY.
£ 100 for my article on the Figure of the Earth from Baldwin the publisher of the Encyclopaedia Metropolitana. — I attended the Greenwich Visitation on June 3rd. — On June 3Oth the Observatory Syndicate made their report : satisfactory.
"On July 6th 1831 I started with my wife and infant son for Edensor, and went on alone to Liverpool. I left for Dublin on the day on which the loss of the ' Rothsay Castle ' was telegraphed, and had a bad voyage, which made me ill during my whole absence. After a little stay in Dublin I went to Armagh to visit Dr Robinson, and thence to Cole- raine and the Giant's Causeway, returning by Belfast and Dublin to Edensor. We returned to Cambridge on Sept. Qth.
" Up to this time the Observatory was furnished with only one large instrument, namely the lo-foot Transit. On Feb. 24th of this year I had received from Thomas Jones (62, Charing Cross) a sketch of the stone pier for mounting the Equatoreal which he was commissioned to make: and the pier was prepared in the spring or summer. On Sept. 2Oth part of the instrument was sent to the Observatory ; other parts followed, and Jones himself came to mount it. On Sept. 1 6th I received Simms's assurance that he was hasten- ing the Mural Circle. — In this autumn I seriously took up the recalculation of my Long Inequality of Venus and the Earth, and worked through it independently ; thus correcting two errors. On Nov. roth I went to Slough, to put my Paper in the hands of Mr Herschel for communication to the Royal Society. The Paper was read on Nov. 24th. — This was the year of the first Meeting of the British Association at York. The next year's meeting was to be at Oxford, and on Oct. 1 7th I received from the Rev. W. Vernon Harcourt an invitation to supply a Report on Astronomy, which I under- took : it employed me much of the winter, and the succeeding spring and summer. — The second edition of my Tracts was ready in October. It contained, besides what was in the first edition, the Planetary Theory, and the Undulatory Theory of Light. The Profit was £80. — On Nov. I4th I presented to
AT CAMBRIDGE OBSERVATORY. 95
the Cambridge Philosophical Society a Paper ' On a remark- able modification of Newton's Rings ' : a pretty good Paper. — In November the Copley Medal was awarded to me by the Royal Society for my advances in Optics. — Amongst miscel- laneous matters I was engaged in correspondence with Col. Colby and Capt. Portlock about the Irish Triangulation and its calculation. Also with the Admiralty on the form of publication of the Greenwich and Cape Observations."
1832
" In January my Examination Paper for Smith's Prizes was prepared as usual. — Two matters (in addition to the daily routine of Observatory work) occupied me at the begin- ning of this year. One was the translation of Encke's Paper in successive numbers of the Astronomische Nachrichten concerning Encke's Comet ; the University Press printed this gratuitously, and I distributed copies, partly by the aid of Capt. Beaufort. — The other was the Report on Astronomy for the British Association, which required much labour. My reading for it was principally in the University Library (possibly some in London), but I borrowed some books from F. Baily, and I wrote to Capt. Beaufort about the possible repetition of Lacaille's Meridian Arc at the Cape of Good Hope. The Report appears to have been finished on May 2nd. — At this time the Reform Bill was under discussion, and one letter written by me (probably at Sheepshanks's request) addressed I think to Mr Drummond, Lord Althorp's secretary, was read in the House of Commons.
" Optics were not neglected. I have some correspondence with Brewster and Faraday. On Mar. 5th I gave the Cam- bridge Philosophical Society a Paper ' On a new Analyzer/ and on Mar. ipth. one 'On Newton's Rings between two sub- stances of different refractive powers,' both Papers satisfac- tory to myself. — On the death of Mr F. Fallows, astronomer at the Cape of Good Hope Observatory, the Admiralty
96 GEORGE BIDDELL AIRY.
appointed Mr Henderson, an Edinburgh lawyer, who had done some little things in astronomical calculation. On Jan. loth I discussed with him observations to be made, and drew up his Official Instructions whigh were sent on Jan. i6th. — On Feb. i6th Sir James South Writes that Encke's Comet is seen : also that with his 1 2-inch achromatic, purchased at Paris, and which he was preparing to mount equatoreally, he had seen the disk of Aldebaran apparently bisected by the Moon's limb. — Capt. Beaufort and D. Gilbert write in March about instructions to Dunlop, the astronomer at Paramatta. I sent a draft to Capt. Beaufort on Apr. 27th.
" The Preface to my 1831 Observations is dated Mar. 2Oth. The distribution of the book would be a few weeks later. — On May 7th I began my Lectures : 5 1 names : I finished on May 29th. — The mounting of the Equatoreal was finished some time before the Syndicate Visitation at the end of May, but Jones's charge appeared to be exorbitant : I believe it was paid at last, but it was considered unfair. — On June 2nd I went to London : I presume to the Greenwich Visitation. — I went to Oxford to the meeting of the British Association (lodging I think with Prof. Rigaud at the Observatory) on June 1 6th, and read part of my Report on Astronomy in the Theatre.
"On June 26th I started with my wife for the Highlands of Scotland. After a short stay at Edensor, we went by Carlisle to Glasgow, and through the Lake District to Inverness. Thence by Auchnanault to Balmacarra, where we were received by Mr Lillingstone. After an expedition in Skye, we returned to Balmacarra, and passed on to Invermoriston, where we were received by Grant of Glenmoriston. We then went to Fort William and Oban, and crossed over to Mull, where we were received by Maclean of Loch Buy. We returned to Oban and on to Edinburgh, where we made a short stay. Then to Melrose, where we were received by Sir D. Brewster, and by Edensor to Cambridge, where we arrived on Sept. I7th.
AT CAMBRIDGE OBSERVATORY. 97
" I received (at Edinburgh I believe) a letter from Arago, writing for the plans of our observing-room shutters. — Mr Vernon Harcourt wrote deprecating the tone of my Report on Astronomy as related to English Astronomers, but I refused to alter a word. — Sheepshanks wrote in September in great anxiety about the Cambridge Circle, for which he thought the pier ought to be raised : I would have no such thing, and arranged it much more conveniently by means of a pit. On Oct. gth Simms says that he will come with the circle immediately, and Jones on Sept. 29th says that he will make some alteration in the equatoreal : thus there was at last a prospect of furnishing the Observatory properly. — On Oct. 9th, I have Encke's thanks for the translation of the Comet Paper. — One of the desiderata which I had pointed out in my Report on Astronomy was the determination of the mass of Jupiter by elongations of the 4th satellite : and as the Equatoreal of the Cambridge Observatory was on the point of coming into use, I determined to employ it for this purpose. It was necessary for the reduction of the observa- tions that I should prepare Tables of the motion of Jupiter's 4th Satellite in a form applicable to computations of dif- ferences of right-ascension. The date of my Tables is Oct. 3rd, 1832. — In October the Observatory Syndicate made their Report : quite satisfactory.
" On Oct. 2Oth Sheepshanks wrote asking my assistance in the Penny Cyclopaedia : I did afterwards write * Gravitation ' and ' Greenwich.' — Capt. Beaufort wrote in November to ask my opinion on the Preface to an edition of Groombridge's Catalogue which had been prepared by H. Taylor: Sheep- shanks also wrote; he had objected to it. This was the beginning of an affair which afterwards gave me great labour. — Vernon Harcourt writes, much offended at some terms which I had used in reference to an office in the British Association.
" The Equatoreal mounting which Troughton and Simms had been preparing for Sir James South's large telescope A. B. 7
98 GEORGE BIDDELL AIRY.
had not entirely succeeded. I have various letters at this time from Sheepshanks and Simms, relating to the disposi- tion which Sir James South shewed to resist every claim till compelled by law to pay it. — A .general election of Members of Parliament was now coming on : Mr Lubbock was candi- date for the University. On Nov. 27th I had a letter from Sedgwick requesting me to write a letter in the newspapers in favour of Lubbock; which I did. On Dec. 7th I have notice of the County voting at Newmarket on Dec. i8th and 1 9th : I walked there to vote for Townley ; he lost the election by two or three votes in several thousands.
" The Mural Circle was now nearly ready in all respects, and it was known that another Assistant would be required. Mr Richardson (one of the Assistants of Greenwich Ob- servatory) and Mr Simms recommended to me Mr Glaisher, who was soon after appointed, and subsequently became an Assistant at Greenwich. — On Dec. 24th I have a letter from Bessel (the first I believe). I think that I had written to him about a general reduction of the Greenwich Planetary Ob- servations, using his Tabulae Regiomontanae as basis, and that this was his reply approving of it.
1833
"On Jan. 4th 1833 my daughter Elizabeth was born. — I prepared an examination paper for Smith's Prizes as usual. — On Jan. 5th I received notice from Simms that he had received payment (£1050) for the Mural Circle from the Vice-Chancellor. About this time the Circle was completely made serviceable, and I (with Mr Glaisher as Assistant) im- mediately began its use. A puzzling apparent defect in the circle (exhibiting itself by the discordance of zenith points obtained by reflection observations on opposite sides of the zenith) shewed itself very early. On Feb. 4th I have letters about it from Sheepshanks and Simms. — On Jan. I7th I received notice from F. Baily that the Astronomical Society had awarded me their Medal for my long inequality of
AT CAMBRIDGE OBSERVATORY. 99
Venus and the Earth : on Feb. 7th I went to London, I suppose to receive the Medal. — I also inspected Sir J. South's telescope, then becoming a matter of litigation, and visited Mr Herschel at Slough: on Feb. I2th I wrote to Sir J. South about the support of the instrument, hoping to remove one of the difficulties in the litigation ; but it produced no effect. — Herschel wrote to me, from Poisson, that Ponte- coulant had verified my Long Inequality.
"Mar. I2th is the date of the Preface to my 1832 volume of Observations: it was of course distributed a few weeks later. — In my Report on Astronomy I had indicated the Mass of Jupiter as a subject requiring fresh investigation. During the last winter I had well employed the Equatoreal in observing elongations in R.A. of the 4th Satellite. To make these available it was necessary to work up the theory carefully, in which I discovered some remarkable errors of Laplace. Some of these, for verification, I submitted to Mr Lubbock, who entirely agreed with me. The date of my first calculations of the Mass of Jupiter is Mar. 1st : and shortly after that I gave an oral account of them to the Cambridge Philosophical Society. The date of my Paper for