Читать книгу Autobiography of Sir George Biddell Airy - George Biddell Airy - Страница 17
PERSONAL SKETCH OF GEORGE BIDDELL AIRY.
ОглавлениеThe 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 absolutely 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 investigated: 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.
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 withdrawing 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 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 unfruitful 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 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 insertions 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 himself 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 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 numerous 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 independence 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 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 abolition 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 professedly 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 correspondence 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 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 confidence 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 Cambridge, 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 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 conversation. He would then play a game or two at cards, read a few pages of a classical or historical book, and retire at 11. 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 enjoyment 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 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 remodelled during his tenure of office. And in many of the matters referred to him, as for instance that of the Lighthouses, 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 experiments in the Cornish mines. This knowledge he afterwards 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 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. Antiquities 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 connection 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 extremely 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, Brunel, 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 connection 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 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 sensitiveness, 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 differences 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 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.