Page:History of the Royal Society.djvu/263

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the Royal Society.
237

Whence you may be pleased to observe:

First, that the recoil of the Piece being hindred only at R or L, whatsoever be the charge of the Powder, the Bullet still misses the Mark, placed at the Mouth of the Gun, on the same side that the recoil is made.

Secondly, That about twelve grains of Powder shoots widest from the Mark at all distances above-mentioned, on the same side that the recoil is made.

Thirdly, That above Forty-eight Grains of Powder shoots wide from the mark, placed at nine foot from the Muzzle of the Piece, on the contrary side to that on which the recoil is made.

The Cause of the first I cannot doubt to be the recoil of the Piece (from the Force of the Powder) before the Bullet be parted from it.

The second is, as I conceive, because with less than twelve Grains the Piece ceaseth to recoil before the Bullet be parted from it. And with more than twelve Grains the Bullet is parted from the Piece before it hath recoiled so far: A greater power not moving a greater weight swifter (horizontally) in the same proportion that it doth the lesser.

And for the third I have this to offer, viz. Because the Mouth of the Gun is moving sidewards whilst the Bullet is going out; therefore the Mouth of the Piece must be contiguous (at least) unto the Bullet on the contrary side to that on which the Piece recoils, some time after the separation made on the other side, and therefore the last impulse of the Bullet from the force of the Powder is on that side the Piece recoils; wherefore the Bullet must necessarily cross the Axis of the Piece, and that with a greater or lesser Angle, according to the force of the Powder, and when this Angle therefore is greater than the Angle of recoil,

then