vat La Face, 
iff angles, an 
‘powder, The fol- 
thas’ Actual 
ihitlers = A 
6 15 $560 
6 4 1650 
4 15 3000 
4 4s 1640 
wg 15 2880 
3 4 1540” 
2 15 3000 
2 6 1724 
Pounds of Ranges in | Pounds of “Ranges in 
Powder. Yards. Powder. Yards 
Bacon sisioy keene | ‘i hee A » 1676 
am oe, 2 {L088 AE. Vn orien” e1ii2 od ae 
Te see, ee, =| 1088 — sy 2, 91568 
ees Tovey eulh (h8 Latisku tates - 1900 
Dilic Ve vois.ecs BROU —_—. » « 1784 
— - « « + 1834 _ oe 0 LS8S 
I era St) oP 1710 24) wiry © . 1660 
— .. - + 1624 Up SE es pee ey 
wee wie DABS | ee be ey 1614 
at ant osteitis ee co, (TOS 
mm ee» + 1740 sie comtys upc IOS 
aa elias ate Be Sees uot 10} sash) OS 
— «+ + « «+ 1708 AS ny be - 1680 
Peis ne > 0 icj0 eee — 1 ee 1696 
wets d-nsel fe 0F 1A ERO ee  Saviaheies IRTP OE 
Sees. ohio! ols ad bas ieee oe) @ 1900 
poe ad aie rw ase 1010 me pe bet e eh 20 
eee ale iets ae Ae ee Sarl creGcets Aes 
for ie nue, - yp 2020 1B Sirw 2000 
Ea a rere 5/8) Soler b Deni oy (OO 
— «+ »\),.«- 1800 —- +: 1940 
=e ce pte le 1566 ey) ey yr) ie 1670 
PETE 8 coc alot oad “9, kOGS 1S Asie & es eisee 1h 900 
— . / ? . 1744 omy * , . . 2000 
se ee ey ce, e702 20 orite p yy 8200 
i = 6 . . . 1690 ——. (> . . . 1682 
See. fo iy.9) 0) ek ae 7 
» Hitherto no al principle had been established 
,. by the numero jas expeeaents of which we have given 
a short account; but the subject of gunnery was now 
destined to receive the most i t improvements 
from the labours of Mr nin Robins, who publish- 
ed an.account of them in 1742, in his New Principles 
‘Gunnery, containing the determination of the force of 
,-and the investigation of the ences in the 
resisting power of the air to swift slow motions: 
5 
GUNNERY. 
In this valuable work, he begins by determ 
"take place in 
shells, 
explosive force of der, —— 
powper, p. 586.) and he found that this force was parce ll 
ing to an elastic fluid like air which existed in a highly Prone" 
condensed state in the der, and being su mg 
parated from it by pth hs expanded and impelled 
the-bullet with prodigious force. 
Mr Robins then proceeds to determine the 
with which gunpowder will impel a shot of a a 
weight from a cannon of given and in or- 
der to com the velocities thus 
real velocities, he invented an instrument called the Bal- 
listic Pendulum, by which he was enabled to measure 
the real velocities of bullets of all kinds with such aceu~ 
racy, that in the case of a bullet moving with a veloci~ 
ty of 1700 feet ved second, the error will neyer amount 
see our article 
to -i,th of the whole. 
With machine he made a t number of expe- 
riments, with musket barrels of aiferent 1 , char 
athe different quantities of powder, an i 
agreement between 
the calculated and o ed velocities is so surprising 
as to establish his theory on the firmest foundation. 
Mr Robins D oy ase to point out the changes which 
e force of gunpowder, from variations in 
the heat.and moisture of ‘the a’ : He deter. 
mines the velocity which the flame of gunpowder ac- 
of different eights and 
ry 
Seen expanding itself, to be 7000 feet per second : 
e ascertains the manner in ‘which the flame of the 
wder impels a ball; placed at a considerable distance 
rom the charge ; and he enumerates the various kinds 
of powder, and describes the best methods of examining 
its : - - 
Mr Robins then treats of the resistance of the air, 
and of the track described’ by the flight of shot and 
He shews, from ime made with the 
dulum, that at different velocities there was 
increase of the resistance over the law of the 
square of the velocity, as the 
“moved quicker. 
He then proves, that a 24 pound ball fired wi a full - 
charge of powder, experiences; when it first issues 
from the piece, a resistance more than 20 times its - 
weight ; that.the paths of projectiles; when the veloci« 
ty of projection is considerable, is not nearly a paras 
bola ;-and that, in their flight, bullets-are not only de- 
pressed beneath their original direction .by the action 
of gravity, but are frequently deflected to the right or 
left of that direction by the action of some other force. 
Robins’ Principles of Gunnery was translated into Ger- 
man by Euler, who heno’ it with learned and va- 
luable pemanent aris } Bei aid beats a 
About eight or ten years e publication 0< 
bing’ Works, the Chevalier D'Arcy published, inthe ha°cnne, 
Memoirs of the Academy for 1751, a Treatise on the tier D’Arcy. 
Theory of Artillery, in which he gives an account of a 
series of experiments made with great care. He em- 
ployed two pendulums, oe one of which he fired 
the ball, while the other, from which the small cannon 
was suspended, served to measure the recoil. These 
experiments were afterwards extended, and published 
in his Essais d'une Theorie de l Ariillerie, which ap- 
peared in, 1760. 
In the year 1746, between the 7th February and the Experi- 
30th of March, a series of iments were made by ments at 
the officers of artillery at Turm, for the pupose of de- aaa in 
termining the charges of powder that give the lar, : 
ranges. The were mounted on a pet of the for- 
tifications of the city, where the axis of the piece was 
30 feet higher than the level of the country where the 
ballistic 
a gradi 
