Popular Science Monthly/Volume 3/May 1873/Sketch of Sir G. B. Airy

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Popular Science Monthly Volume 3 May 1873  (1873) 
Sketch of Sir G. B. Airy
 
PSM V03 D008 George Biddell Airy.jpg

Sir George Biddell Airy


SKETCH OF SIR G. B. AIRY.

SIR GEORGE BIDDELL AIRY, the Astronomer Royal, was born on the 27th of June, 1801, at Alnwick, in Northumberland. His education was first cared for at two private academies, now at Hereford, now at Colchester. From the Colchester Grammar-School, when eighteen years of age, he went, in 1819, to Trinity College, Cambridge. Three years afterward he was elected to a scholarship. In 1823, on his graduating B. A., young Airy came out as Senior Wrangler. In 1824 he obtained his Fellowship at Trinity. His degree of M. A. was taken in 1826, and he was simultaneously elected, though only then in his twenty-fifth year, as Lucasian Professor at Cambridge. Illustrious philosophers like Barrow and Newton had preceded him in the occupation of that historic chair. Latterly, however, the office had become, in a great measure, purely honorary, and might almost be said to have degenerated into a sinecure.

Prof. Airy, once elevated to that position, determined to avail himself of his professorship to the advantage alike of himself and the university. Consequent upon this determination, he for nearly ten years together—namely, from 1827 to 1836—delivered, with admirable effect, a series of public lectures on experimental philosophy, by which his scientific reputation was very considerably advanced. The series was all the more remarkable, inasmuch as it was one of the earliest means of effectively illustrating the marvellous phenomena constituting the now almost universally adopted undulatory theory of light. Two years after Prof. Airy's induction into the chair established by Lucas, the estimation in which he was held at the university was still further signalized by his election to the Plumian Professorship. Nominated to that post of authority and honor, he at once obtained, by right of his position, the supreme command of the Cambridge Observatory.

Already, even then, he began those remarkable improvements in the method of calculating and publishing the observations which eventually became the law at Greenwich and at all the other great observatories. As indicative of the energy and daring of his innovations at Cambridge, he superintended the construction and mounting, one after another, of a series of renowned astronomical instruments. In that observatory, he brought into use a noble specimen of the equatorial, being that peculiar description of telescope which has its fixed axis so directed to the pole of the heavens that the tube may be readily made to follow any star by a single motion. There, moreover, he brought into effective employment a mural circle of admirable construction, bearing a telescope which revolves in the plane of the meridian, the whole being rigidly bound into some immovable structure of ponderous masonry. Prof. Airy, in his thirty-fourth year, became Astronomer Royal. Thirty-eight years have since elapsed. Under his directions, it is hardly too much to say that the organization of the establishment at Greenwich has been completely transformed. He has given great regularity to its minute and multiform proceedings. He has contrived to establish newer and sounder methods of calculation and publication. He has introduced, constructed, mounted, and employed, a series of novel instruments for the advancement of astronomic research. Perhaps the finest transit-circle at present anywhere to be found is the one he there constructed in 1860, the circles being no less than six feet in diameter, and the telescope affixed between the two graduated disks being twelve feet long, and having an object-glass of as many as eight inches in aperture. Through this splendid apparatus the altitude of the stars, as well as the time of meridian passage, is now unerringly marked at the great national observatory. But the greatest of all the instruments established by him at Greenwich is a large, first-class equatorium, well known among astronomers.

During Sir George Airy's rule at the observatory he has, in the midst of his other labors, reduced the Greenwich observations of the moon and of the planets from 1750 down to the present tfme. Incidentally he has thrown considerable light on ancient chronology by his ingenious calculation of some of the most renowned of historical eclipses. Thrice the Astronomer Royal has taken occasion to visit the European Continent for the purpose of making more accurate observations upon the solar eclipse then eagerly anticipated. In 1854 he approximated more nearly than any previous investigation had done to the weight of the earth, through a series of experiments on the relative vibration of a pendulum at the top and bottom of Harton Coal-pit.

Sir George Airy has been repeatedly called into council on matters of grave difficulty by the government. He was chairman of the royal commission empowered to supervise the delicate process of contriving new standards of length and of weight, the old standards having been destroyed in 1834 in the conflagration of the Houses of Parliament. He was consulted some years afterward by the government in respect to the bewildering disturbance of the magnetic compass in iron-built ships-of-war. Thereupon he contrived an ingenious system of mechanical construction, through a combination of magnets and iron. The result was successful, and the system generally adopted. He conducted the astronomical observations necessary to the drawing of the boundary-line now traceable on the map of the New World between the Canadas and the United States. During the battle of the gauges in the railway world Sir George Airy strenuously advocated the narrow gauge, and he just as energetically advocates the adoption of a decimal currency. The writings of the Astronomer Royal are numerous. He has contributed largely to the Cambridge Transactions and the Philosophical Transactions. His pen has notably illustrated the memoirs of the Astronomical Society. He has written abundantly for the Philosophical Magazine, and still more abundantly, under his reversed initials, A. B. G., in the columns of the Athenœum. His principal works, however, are those which may be here rapidly enumerated: "Gravitation," published in 1837, was written originally for the "Penny Cyclopædia." "Mathematical Tracts" have reached a fourth edition, as have also his "Ipswich Lectures on Astronomy." In 1861 appeared his treatise on "Errors of Observation;" in 1869 his treatise on "Sound;" and in 1870 his treatise on "Magnetism." Sir George Airy's well-known work on "Trigonometry" was published in 1855. Another work of his, entitled "Figure of the Earth," has yet to be named, as well as the luminous paper on "Tides and Waves," contributed by him, first of all, to the "Encyclopædia Metropolitana." Even while simply Professor of Astronomy at Cambridge his "Astronomical Observations," issuing from the press between 1829 and 1838, extended to nine quarto volumes, and were adopted at once as models for that class of publication.

Sir George Airy has received the Lalande Gold Medal of the French Institute in honor of his important discoveries in astronomy. For his successful optical theories he has had awarded to him the Copley Gold Medal of the Royal Society. The Royal Gold Medal of the same society has been given to him in recompense for his tidal investigations. Twice the Gold Medal of the Royal Astronomical Society has been his—first, for his discovery of an inequality of long period in the movements of Venus and the earth; secondly, in return for his reduction of the planetary observations. He has been enrolled among the most honored members of the Royal Astronomical Society, of the Cambridge Philosophical Society, and of the Institute of Civil Engineers. For many years past he has been among the foreign correspondents of the Institute of France, as well as of several other scientific academies on the Continent. He has received honorary degrees of D. C. L. and LL. D. from each of the three great universities—Oxford, Cambridge, and Edinburgh. On May 17, 1872, Sir George was gazetted a Knight of the Bath. His claim upon the remembrance of posterity, however, will be that of having occupied with distinguished ability the post of Astronomer Royal of Great Britain during considerably more than the lifetime of a whole generation.

 

The Illustrated Review, a London biographical and literary periodical, to which we are indebted for the preceding statements, remarks that, since the death of Sir John Herschel, on the 11th of May, 1871, Sir George Airy, the Astronomer Royal, is the admitted master of the sublime science. There are other eminent English astronomers—as John Hinde, the discoverer of many asteroids, and John Adams, also a Cambridge Senior Wrangler and the rival of Urban Leverrier, who groped his way by mathematical calculation to the discovery of the position of the hitherto unknown planet Neptune. If incidents as brilliant and remarkable as these are wanting in the history of Sir George Airy, his claims to respect are equally valuable, solid, and enduring.