OP ARTS AND SCIENCES : MAY 29, 1866. 126 



Ponticoulant, and Lubbock, who, in 1846, furnished the means of con- 

 structing tables of the moon without any empirical hypothesis] the 

 credit of first bringing; the Lunar Tables within the limits of error of 

 observation, and thereby of bringing to perfection the solution of the 

 problem of finding the longitude at sea by means of lunar observations." 

 Of the excellence of the work here referred to, Sir J. Lubbock appears 

 to have first been made aware by its near agreement with the formula 

 from which the American Tables of the Moon were constructed, and 

 the very close agreement of these tables with observation. 



Sir William Rowan Hamilton, Astronomer Royal for Ireland, 

 son of Ai'chibald Hamilton, Esq., of Dublin, was born in that city, 

 August 5, 1805, and early put under the tuition of his uncle, Rev. James 

 Hamilton, curate of Trim, by whom his remarkable taste and ability for 

 learning languages were so much fostered, that by the age of fourteen he 

 had made great progress in thirteen languages besides his own, in which 

 he also showed the finest rhetorical powei's. His taste for mathematics 

 (perhaps derived from his mother, whose maiden name was Sarah Hut- 

 ton, and who was of the family distinguished in that science) was so 

 strong that it led him, with very little aid from tutors, to rapid self- 

 directed progress. He began geometry at the age of ten, algebra at 

 twelve ; at seventeen he had thoroughly mastered the calculus, and at 

 nineteen, while an undergi'aduate at Dublin, laid the foundations of a 

 new science ; at the age of twenty-two, not yet having taken his Bache- 

 lor's degree, he was made Andrews Professor of Astronomy in his own 

 University ; not because he was an astronomer, nor because his Alma 

 Mater wished him to become an astronomer ; but because she wisely 

 wished to secure the residence of a son of such rare genius and virtue. 

 His mathematical writings consist of a single volume. Lectures on 

 Quaternions, published in 1853, and of numerous contributions to the 

 Transactions of the Royal Irish Academy, from 1828 to 1847 ; to the 

 Philosophical Magazine, from 1831 to 1861 ; and to the first four vol- 

 umes of the Cambridge and Dublin Mathematical Journal. These 

 contributions all relate to pure Mathematics or to Analytical Mechanics, 

 — his wealth of metaphysical, poetical, and philological learning and 

 ability never luring him from his chosen walk, — and all show a mas- 

 ter's hand. 



His papers on Optics were the first example of extended investiga- 

 tions into the phenomena of motion abstracted from the idea of force ; 

 and his prediction of conical refraction, having been verified by subse- 



