Royal Society. 527 



the mathematical tripos in 1787. After practising for some years 

 at the bar, he was appointed Chief Justice of Ceylon, a station 

 which he filled for several years with great advantage to that co- 

 lony. On his return from the East, he was made Auditor of the 

 Exchequer, and also received from his uncle Lord Ellenborough the 

 appointment of Master of the Crown Office. He was an intimate 

 friend of Wollaston and Tennant ; and though withdrawn by his 

 pursuits from the active cultivation of science, he continued 

 throughout his life to feel a deep interest in its progress. His 

 acquaintance with classical and general literature was unusually 

 extensive and varied, and he had the happiness of witnessing in his 

 sons the successful cultivation of those studies which other and 

 more absorbing duties had compelled him to abandon. Mr. Lush- 

 ington was a man of a cheerful temper, of very courteous and 

 pleasing manners, temperate and tolerant in all his opinions, and 

 exemjilary in the discharge both of his public and private duties : 

 few persons have ever been more sincerely beloved either by their 

 friends or by the members of their families. 



Mr. Geoi-ge Saunders was formerly architect to the British Mu- 

 seum, where he built the Townley Gallery : he was also a diligent 

 and learned antiquary, and the author of a very interesting and va~ 

 luable paper in the twenty-sixth volume of the Archaeologia, con- 

 taining the results of an inquiry concerning the condition and ex- 

 tent of the city of Westminster at various periods of our history. 



The only foreign members whom the Royal Society has lost 

 during the last year are the Baron de Prony, one of the most di- 

 stinguished engineers and mathematicians of the age ; and the ve- 

 nerable Pierre Prevost, formerly Professor of Natural Philosophy in 

 the University of Geneva. 



Gaspard Clair Francois Marie Riche de Prony, was born in the 

 department of the Rhone in 1755, and became a pupil, at an early 

 age, of the Ecole des Ponts et Chaussees, where he pui'sued his 

 mathematical and other studies with great application, and with 

 more than common success. He was subequently employed, as an 

 adjunct of M. Perronet, the chief of that school, in many important 

 works, and particularly in the restoration of the Port of Dunkirk ; 

 and in 1786, he drew up the engineering plan for the erection of 

 the Pont Louis XVI., and was employed in superintending its exe- 

 cution. M. de Prony had already appeared before the public, first 

 as' the translator of General Roy's " Account of the Methods em- 

 ployed for the Measurement of the Base on Hounslow Pleath," which 

 was the basis of the most considerable geodesical operation which 

 had at that time been undertaken ; and subsequently, as the author 

 of an essay of considerable merit, " On the Construction of Indeter- 

 minate Equations of the Second Degree." In 1790 and 1797, ap- 

 peared his great work, in two large volumes, entitled Nouvelle Ar- 

 chitecture Hydraulique, which is a very complete and systematic 

 treatise on Mechanics, Hydrostatics and Hydraulics, and more par- 

 ticularly on the principles of the steam-engine and hydraulical en- 

 gineering. In 1792 he was appointed to superintend the execution 



