PNEUMATICS. 279 



time of acquiring a velocity differing from it, by 

 any quantity, however small, is finite, and can ea- 

 sily be assigned. 



375. The great problem in gunnery, viz. having 

 given the weight, the magnitude, the direction, 

 and the velocity of a projectile, to determine its 

 path through the air, supposing the law of resis- 

 tance to be known, is very difficult, and the solu- 

 tions of it hitherto given, have not led to results 

 easily applicable to practice. 



An approximation has been given by NEWTON, and 

 complete solutions by EULER and LE GENDRE. 

 Prin. Math. lib. n. Prop. 10. EULER'S Remarks 

 on ROBINS, BROWN'S translation, p. 322., &c. LE 

 GENDRE'S solution is in FRANCOEUR'S Mecanigue, 

 p. 196., &c. 3d edit. 



Dr HUTTON of Woolwich is in possession of many va- 

 luable materials relative to this problem, furnished 

 by his own experiments, and there is reason to ex- 

 pect a more useful solution than has yet been gi- 

 ven, from one who unites profound mathematical 

 knowledge with great practical skill. 



D'ANTONI has proposed a method of determining by 

 experiment an indefinite number of points in the 

 path of the same projectile. 



If a series of stations, one above another, be taken on 

 the declivity of a hill, at the bottom of which there 



is 



