THACT 34.

IN GUNNERY, 1191.

151

In the tables at art. 191, 192, 193, are given general ab-stracts of the results of the experiments, being the mediumsof the best rounds with the different charges, distances, &c,as computed from the experiments, and all reduced to thesame circumstances, viz,

Ball’s weight - - - 6lb lioz,

Ditto diameter - - 3‘55 inches

Eprouvette - - - 43

Barometer - - - 30

By comparing together the effects of the medium andlight guns, of equal length nearly, it appears that there is nosensible difference between their velocities with equal chargesof powder, though the one gun weighs nearly double of theother: whence it may be inferred, that their difference inweight has no sensible effect on the ball’s velocity.—And thesame thing happens by comparing together the velocities,when the gun is suspended like a pendulum, vibrating freelywhen fired, and when it is mounted on a sliding carriagewhich can recoil but very little, or even when the recoil iswholly prevented.—It also appears that the velocities arisingfrom the firing of different charges, are nearly in the propor-tion of the square roots of the quantities or weights of pow-der.—By comparing together the long gun, of 80 inchesbore, and the short ones, of 56, it appears that there is butlittle gained in velocity, in comparison of the length; thegain in velocity by the long gun being only from to ^ ofthe whole.

The comparison between the long and short guns beingsettled, the experiments were prosecuted with the longgun only, as sufficient for determining the other points ofenquiry.

196. It appears, from the table of velocities, with whichthe balls strike the pendulum from different distances, thatthey continually decrease as those distances increase ; theirdifferences showing the quantity of velocity lost by passingthrough certain spaces of air; from which losses of velocity