MARQUIS OF CALIGNY. 453 



favorably upon it, that the Academy awarded him the Montyon 

 Prize* in Mechanics, which had just been established. CaJigny's in- 

 vention is thus described in the report of the committee: " The happy 

 idea which distinguishes this machine, and characterizes it as a veritable 

 invention, is the discharge through a vertical tube, after an upward 

 oscillation, without the loss of any living force except that consumed 

 by friction ; that is to say, by depressing very slightly the centre of 

 gravity of the fluid column to be discharged. Without doubt the 

 machiue appears simple both in conception and construction, but this 

 simplicity only enhances its merits." 



From this time Caligny's success was assured. He was the dis- 

 coverer of a new branch of hydraulics, namely, that relating to 

 oscillating liquids ; and he published from time to time accounts of his 

 researches, which were remarkable both for the methods employed and 

 the results obtained. To these researches he devoted his life, never 

 attaching himself to any administration, nor taking part in any private 

 enterprise; he even refused to take patents for his inventions, prefer- 

 ring to devote himself with indefatigable zeal to the disinterested 

 pursuit of science. 



Ou several occasions his rights of priority were disputed, but they 

 were always easily established by means of his publications in the 

 transactions of the French Academy. His investigations were brought 

 together in 1883, in two volumes entitled, " Theoretical and Exper- 

 imental Researches on the Oscillations of Water and Hydraulic 

 Machines with Liquid Oscillating Columns." Prizes were awarded 

 to his machines at all the International Exhibitions, and he received 

 numerous diplomas from different European Academies. 



The following succinct account of his first apparatus is thus given 

 by M. Boussinesq : — 



" From the bottom of a reservoir containing water at rest, a long 

 horizontal or slightly inclined conduit issues, having its further end 

 terminated by a vertical pipe of the same diameter as the conduit, and 

 rising some distance above the level of the reservoir. It is proposed 

 to raise and discharge the water from the top of this pipe. For this 

 purpose, a valve movable around a horizontal axis, manipulated from 

 without, separates the empty vertical pipe from the conduit filled with 

 water under pressure. The valve, being at a given moment released, 

 is raised by the water which begins to rise in the pipe, and that in the 

 conduit also, but only little by little, on account of its great mass. 



* This prize consists of a gold medal valued at 500 francs. 



