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 any-
