OF GUN-POWDER. 4t

before the wad is displaced. If, on the contrary, part of theplatform be raised, the same force that will draw out theWad will not be sufficient to draw the gun up the inclinedplane. Similar varieties occur in the recoil, when the ele-vation of the gun is altered, or the wheels turn more freelyon the axle-tree.

To give to this question a practical solution, with respectto charges that all take tire in the gun ; let the gun and car-riage be considered as one body=C, the wads and shot=P,the length of the bore from the (hot to the muzzle = D, the

PD

recoil will be=-. Let one round be fired with a wad

C

over the powder, and the recoil = A. Let a second be firedwith the addition of a shot, the recoil — B will be greaterPD BPD

than A; and A : B :: -:-= the length of the recoil

C AC

in the time that the shot is passing along the gun. This ex-periment having been made with a thirty-two pounder,charged with common powder, and sired horizontally on aBPD

horizontal platform-= i an inch. So that if the plat-

AC

form be very solid and even for 4- an inch, at the spot onwhich the wheels and trail of the carriage rest, the remain-der of the platform is only useful in facilitating the operations

BPD

of the artillery-men : indeed, as the value-may from

AC

circumstances vary a little, allowance should be made for it.

ioo. Let the second effect (90. N°2.), viz. that thecharge -which gives the longeji range in pieces of small calibre ,is proportionally greater than the charge which gives the lon-gest ranges in pieces of large calibre , be now considered.This effect, which constantly appeared in the foregoing ex-periments, could only proceed from the size of the vent beingequal in the four guns, and from the wads being rammedwith the same force. From the former circumstance, a re-latively greater degree of fire is produced in the small guns ;and from the force with which the wads arc rammed, thepowder is more compact, and the charge adhering closer to