Deceased Fellows : Mr. Davies Gilbert. 63 



Angular Velocities*," in which he first distinctly defined and made 

 known to men of science what is termed the duty of steam-engines, 

 from the correct observation of which so many important practical 

 improvements have followed : — " On the Nature of Negative and 

 Imaginary Quantitiesf ," which contains many ingenious views, al- 

 though they have been in a great measure superseded by later 

 speculations on this subject]:. Mr. Gilbert was a mathematician of 

 the old school; but the papers to which we have just referred are 

 very creditable specimens of the clearness with which he appre- 

 liended the bearing of some simple theoretical truths upon very 

 important practical questions. 



He became President of this Society in 1828, on the resigna- 

 tion of Sir Humphry Davy ; a situation from which he retired in 

 1831. He continued, however, for the remainder of his life, to take 

 a prominent part in the concerns of the Society ; and there are few 

 of my brother-Fellows, ^^■hom I have now the honour, of addressing, 

 who have not had opportunities of observing and appreciating his 

 constant zeal for the interests of science, the variety and philoso- 

 phical character of his conversation, the simple and unaffected elo- 

 quence of his public addresses^, and, above all, that sweetness of 

 temper and kindness of heart which beamed forth in the expression 

 of those truly classical and benevolent features, which one of the 

 most accomplished of our artists (lumself a brother-FelloM') has so 

 happily perpetuated in the portrait which adorns these walls. The 

 very absence of that inflexibility of purpose and of opinion which 

 some might consider essential to the perfection of the character of 

 a philosopher, seemed, in his case, the proper developement of that 

 natural benevolence and humanity which made him so justly beloved 

 in every relation of life, whether as a husband, a father, and a brother, 

 — as a master, a landlord, and a friend. 



Mr. Gilbert m as the author and editor of several antiquarian and 

 otlier works relating to his native county, whose interests he always 

 laboured to promote with more than common zeal and patriotism. 

 He was President of the Cornish Geological Society from the period 

 of its first establisliment in 1814, and he never omitted attending 

 its meetings, though on the last occasion he was so weak as to be 

 compelled to resign the chair to liis friend and countryman Sir 

 Charles Lemon. In 1808, he married Miss Gilbert, and assumed 

 her name in 1817, on succeeding to a very large property in 

 Sussex. The same simple and unaffected character which distin- 

 guislied him in jjublic life was still mon; conspicuous in his domestic 

 relations. He died on the 24th of December last, and his body was 



• For 1830, Part I. p. 121. t For 1831, Partll. p. 341. 



\_l Ahstracis of the two pajjers hero icfcned to will be found in Pliil. 

 Mag. and Annals, N. S., vol. vii. p. 1 11), vul. ix. p. 37. Mr. Gilbert 

 communicated a j)aper on the Regular or Platonic Solids, in Phil. .Mag. and 

 Annals, N. S. vol. iii. p. Hil ; and in vol. ix. p. 200, appears his original 

 statement respecting llic legacy of the late Karl of Hridgcwater.] 



[§ Addresses dehvered to tlie Royal Society by Mr. Gilbert, will be 

 found in Phil. Mag. and Annals, N. S. vol. iii. p. 50, vol. vii. p. 33, and 

 vol. ix. p, 39, — Edit.] 



