4

NEW EXPERIMENTS

TRACT 34.

The general weight of the ball was 16 oz 14 dr ; exceptn° IS, which was 1 oz 10dr; and n° 14 was without anyball.

Here, and in all the future daj's, the chords of vibration,of both gun and pendulum, are expressed in 1000th partsof the radius.

The Gun was n° 1 . — We began this day with the weightof the -gun and its iron frame only, without any of theleaden weights. Then the one set of weights was put on atn° 10, and the other at n° 12. This was done to try theeffects of .different weights of gun on the velocity of theball, experimentally to correct a common error which hadbeen adopted from time immemorial, by professional men,namely, that heavier guns, catcris paribus, give the greatervelocities. The erroneousness of which opinion is provedby the experiments of this and some of the following days.And it is needless to prove a priori to scientific men, thatthe difference in the effects cannot be rendered sensible byany measurements which we-can make of the velocity.

The Pendulum was the block of last year, with a newcore, and a facing of sheet lead. Its weight, taken thismorning, was 627 lb.

The plugs weighed 7 ounces to 11 inches, on an average ;which proportion may always be used in future, at leasttill another be mentioned.

The 8th n° is doubtful, and is omitted in the medium.

The 14th was with powder only, like the first six. Andthe 15th was without ball, having only a wad made of junk,weighing 1 oz 10 dr. This made a small impression, ofabout half an inch deep, in the face of the pendulum, andrebounded back. And it struck the pendulum at more than6 inches above the line of direction.

Note, the centre of the pendulum, as before, is at 88'7inches below the axis. And the value of i, for the meandistance of the points struck, is 88'4.

By comparing together the first 6 rounds, which areall with the same weight of gun, we find that the mean

*