1865.] President's Address. 493 



the rifle, a range fully equal to that of powder, and, in experiments at the 

 School of Musketry at Hythe, under the superintendence of Major-General 

 Hay, has made excellent shooting, producing diagrams at 1000 yards, 

 hardly, if at all, inferior to those obtained from the best small-bore rifles 

 of the day. These diagrams were obtained with a Whitworth- Rifle : in 

 the first, 10 consecutive shots were fired at 1000 yards, with a mean radial 

 deviation of T65 foot; in the second, 9 consecutive shots at 1000 

 yards, giving a mean radial deviation of 2'02 feet. And in the third, 20 

 consecutive shots were fired at 1000 yards, giving a mean radial deviation 

 of 2-43 feet. The charge in all cases was 25 grains of gun-cotton, the 

 angle varying from 3 to 3 3'. 



The cartridges with which these shots were fired were made by hand : 

 the defect of cartridges so made is obvious, viz., that they may not be 

 strictly uniform. But this is an inconvenience remediable by the employ- 

 ment of very simple machinery. 



In preliminary trials above 2000 rounds have been fired out of one and 

 the same rifle, without occasioning the slightest injury to the piece. 



The advantages of the cotton charges were manifest in the diminution 

 of recoil and smoke, and in the entire absence of fouling. 



The demand for cotton charges for sporting-purposes has become very 

 considerable since the shooting-season commenced, and they are under- 

 stood to have given very general satisfaction. 



It is not unreasonable to anticipate that the principles of construction of 

 the cartridges which have proved so successful in the adaptation to small 

 arms, may eventually, with suitable modifications, make cotton available 

 for iron ordnance, as a substitute, in a greater or less degree, for powder, 

 which is far more dangerous in manufacture and storage. As far as has 

 been yet tried, the cotton is found to keep perfectly well for any length of 

 time submerged in distilled water. 



I proceed to the award of the Medals : 



The Council has awarded the Copley Medal to M. Michel Chasles, For. 

 Mem. U.S., for his Historical and Original Researches in Pure Geometry. 



The historical and original researches of Chasles extend over a period 

 of about forty years. Throughout this time he has devoted his energies, 

 with a constancy of purpose rarely equalled, to the restoration and ex- 

 tension of those purely geometrical methods which, bequeathed to us from 

 antiquity, had their growth arrested during the middle ages, and their utility 

 temporarily eclipsed by the brilliant discovery of coordinate geometry by 

 Descartes. In his well-known ' History of the Origin and Development of 

 Geometrical Methods,' published in 1837 and crowned by the Academy 

 of Brussels, Chasles thus expresses what has proved to be the leading object 

 of his life's labours : 



" I propose to show, so far as my feeble means will permit, that in a 

 nuiltitude of questions the doctrines of pure geometry most frequently 

 present to us that easy and natural path which, penetrating to the very 



