VOL. II.] PHILOSOPHICAL TRANSACTIONS. l6(i 



Experiments for Iinproving the Art of Gunnery. By Sir Robert 



Moray. N" 26, p. 473. 



I. To know how far a gun shoots point blank, that is, near the level of the 

 cylinder of the piece. On a fit platform, place and point the gun at a mark, as 

 large as the bullet, at 50, 6o, or more yards distant, so as the under side of the 

 mark may be in the same level or line with the under side of the cylinder of the 

 piece. Then between the gun and the mark, at several distances, place pieces 

 of canvas, sheets of paper pasted together, or the like, on stakes fixed in the 

 ground, so that the under side being level with the horizon, may just touch 

 the visual line passing from the eye to the upper side of the mark, when the 

 eye is in the line drawn from it to the upper side of the cylinder of the gun ; 

 the canvas being so broad and long that if the bullet pass through it two or 

 three feet higher than the level of the mark or of either hand, the hole it makes 

 may show how much it flies higher than the level of that place. If the bullet falls 

 lower than the mark and touch not the canvas, the gun may be next time raised 

 a little, and so on till the bullet hit the mark, or as high as it : And if at first it 

 fall as high as the mark and cut the canvas, the mark and canvas may be 

 brought nearer the gun : Afterwards the mark may be removed to greater and 

 greater distances, till, to hit the mark, it fly higher than some or all the inter- 

 posed canvases: And thus the experiment is to be repeated and varied at 

 pleasure. 



II. To know what quantity of powder is the just charge for any piece, so as 

 it makes the farthest shot, and the powder all fires. 



1 . Elevate the gun to a mean random, as of 20 or 25 degrees, and fire it with 

 the ordinary charge of powder, in some convenient ground where the fall of the 

 bullet may be easily seen, and measure the distance to the hole made by the 

 bullet. 2. Then, instead of a full charge of powder used in the first shot, take 

 -jig- part less, or some such proportion, for the next trial. 3. For a third, 

 fourth, or more trials, diminish still the quantity of powder by ^i^ at a time^ 

 till the range be considerably shorter than at first. 4. Then take -j^ more 

 than the first charge, and do all things else as before, and so continue more 

 trials, increasing always the quantity of powder in the same proportion every 

 new trial, till you find the increase of the charge does not make the piece carry 

 further. 5. The right charge being found, the greatest random is to be sought 

 by trying all randoms, elevating the gun more and more, by degrees at a time. 



III. To know what gun shoots farthest : 



1, A gun to be prepared of much more than the ordinary length, and to be 



