armies, might give the first hint ; and 
Schwartz, to whom the invention of gun- 
powder has been erroneously ascribed, on 
account of the accident above-mentioned 
under the article Gun, might have been the 
first who actually applied it in this way. 
T he first species of artillery, however, 
which were charged with gunpowder and 
stone bullets of a prodigious size, were of 
very clumsyaml inconvenient structure and 
weight. Thus, when Mahomet the 2d be- 
sieged Constantinople, in 1453, he battered 
the walls with stones of this kind, and with 
pieces of the calibre of 1200 pounds; which 
could not be fired more than four times a day. 
For the last 200 years, the formation of 
cannon has been very little improved : the 
battering cannon now approved, are those 
that were formerly called demi-cannon, car- 
rying a ball of 24 pounds weight; this weight 
having been found fully sufficient. The me- 
thod also of making a breach, by first cutting 
off the whole wall as low as possible before 
its upper part is attempted to be beaten 
down, seems to be a considerable modern 
improvement in the practical part of gun- 
nery ; but the most considerable improvement 
in the practice, is the method of tiring 
with small quantities of powder, and elevaF 
ing the piece but a little, so that the bul- 
let may just go clear of the parapet of the 
enemy, and drop into their works, called ri- 
cochet firing: for by this means the ball, 
coming to the ground" at a small angle, and 
with a small velocity, does not bury itself, 
but bounds or rolls along a great way, de- 
stroying all before it. 
The Italians' were the first people that 
made any attempts to ascertain the theory 
of projectiles, which they did about the be- 
ginning of the 16th century. It was then 
determined, that the greatest range of a shot 
was when discharged at an elevation of 45 
degrees ; and that no part of the path de- 
scribed by a ball is a right fine. See Projec- 
tiles. 
Mr. Robins informs us, in the preface to 
his New Principles of Gunnery, that he had 
met with no more than four authors who had 
treated experimentally on this subject. The 
first of these is Goll'ado, in 1642, who lias 
given the ranges of a falconet, carrying a 
three-pound shot, to every point of the gun- 
ner’s quadrant, each point being the 12th 
part, or 7 degrees and a half. But from his 
numbers it is manifest that the piece was not 
charged with its usual allotment of powder. 
It is extraordinary that before Mr. Robins, 
there were but four authors who had treated 
experimentally on gunnery, and those to 
little purpose; but the treatise of Mr. Ro- 
bins is still regarded as the foundation of 
the science. 
The first thing considered by him, 
and which is indeed the foundation of all 
other particulars relating to gunnerv, is the 
explosive force of gunpowder. The "intensity 
of this force Mr. Robins ascertained in diffe- 
rent ways. One of these is by firing the 
powder in the air, thus: A small" quantity of 
the powder is placed in the upper part of a 
glass tube, and the lower part of the tube is 
immerged in water, the water being made to 
rise so near the top, that only a small portion 
of air is left in that part where the powder 
is placed ; in this situation the communica- 
tion between the upper part of the tube and 
GUNNERY. 
the external air being closed, the powder is 
fired by means of a burning-glass, or other- 
wise; the water descends upon the explosion, 
and stan ;s lov er in the tube than before, by 
a space proportioned to the quantity of 
powder fired. Another was by firing the. 
powder in vacuo, viz. in an exhausted re- 
ceiver, by dropping the grains of powder 
upon a hot iron excluded in the receiver. 
For the result of these experiments, see 
Gun-powder. 
Having determined the force of the gitu- 
powder, or intensity of the agent by which 
the projectile is lobe Urged, Mr. Robins next 
determined the effects it will produce, or the 
velocity with which it will impel a shot of a 
given weight from a piece of ordnance of 
given dimensions ; which is a problem strictly 
limited, and perfectly soluble by mathemati- 
cal rules, and is in general this : Given the 
first force, and the law of its variation, to de- 
termine the velocity with which it will impel 
a given body in passing through a given space, 
which is the length of the bore ofthe gun. 
In the solution of this problem, Mr. Ro- 
bins assumes these two postulates, viz. 1. 
That the action of the powder on the bullet 
ceases as soon as tiie bullet is out of the piece; 
and 2d. That all the powder of the charge is 
fired and converted into elastic fluid before 
the bullet is sensibly moved from its place: 
assumptions which for good reasons are found 
to be in many cases very near the truth. It 
is to be noted also, that the law by which the 
force of the elastic fluid varies, is this; viz. 
that its intensity is directly as its density, or 
reciprocally proportional to the space it occu- 
pies, being so much the stronger as the space 
is less ; a principle well known, and common 
to all elastic fluids. Upon these principles 
then Mr. Robins resolves this problem, by 
means of the 39th proposition of Newton’s 
Principal, in a direct way, and the result is 
equivalent to this theorem, where the quan- 
tities are expressed by algebraic symbols ; 
viz. the velocity of the ball 
/ 10 « /, ' 
v ~ 2 t ISO k / — X log. — . 
V cd a 
- / 22 Sad' If 
or — 100 , j x log. — ; whence 
. x to a 
D is the velocity of the ball, 
a the length of the charge of powder, 
b the whole length of the bore, 
c the s P e c. grav. of the ball, or wt. of a cubic 
foot of the same matter in ounces, 
d the diam. of the bore, 
-w the wt. of the ball in ounces. 
For example, Suppose a ~ inc., I — 45 inc., 
c — 1 1 343 oz. for a ball of lead, and d ~ J inc. ; 
then -j — 27130 y / 2L. X log. 'i?= 1674 
feet per second, the velocity of the ball. 
Or, if the wt. of the bullet be iv — l_9_ oz — 
2 0 ’ 
s/- 
X log. 
29 X 32 
— 1674 feet, as before. 
“Having in this proposition,” says j\ 
Robins, “ shewn how the velocity, which a 
bullet acquires from the force of pow d 
may be computed upon the principles of t 
theory iaiu down in the preceding proi 
sitions; we shall next shew, that the act! 
velocities, with which bullets of different ma 
nituaes are impelled from different piec< 
885 
with different quantities of'pbwder,.^re rer.il v 
the same with the velocities assigned by these- 
computations; and consequently, that this 
theory ot the force of powder, here delivered, 
does unquestionably ascertain the true action 
and modification of tniss normous power. 
“ But in order to compare the velocities 
communicated to bullets by the explosion, 
with the velocities resulting from the theory 
by computation, it is necessary that the ac- 
tual velocities with which bullets move, 
should be capable of being discovered, which 
yet is impossible to be done by am methods 
hitherto made public. The only means hi- 
therto practised by others for that purpose, 
have been either by observing tiie time of 
tiie bight of the shot through a given space; 
or by measuring the range of the shot at a 
given elevation, and thence computing, on 
the parabolic hypothesis, what velocity would 
produce this range. r l he first method la- 
bours under this insurmountable difficulty,, 
that the velocities of these bodies are often 
so swift, and consequently the time observed 
is so short, that an imperceptible error in that 
time may occasion an error in the velocity 
thus found, of 2, 3, 4, 5, or 600 feet in a 
second. -1 he other method is so fallacious, 
frcm.jthe resistance of the air (to which ine- 
quality the first is also liable), that the ve- 
locities thus assigned may not be perhaps 
the tenth part of the actual velocities sought. 
“ to remedy then these inconveniences, 
I have invented a new method of finding the 
real velocities of bullets of all kinds; and this 
to such a degree ot exactness (which may 
be augmented too at pleasure), that in a bul- 
let moving with a velocity of 1700 feet in \", 
the error in the estimation of it need never 
amount to its 500th part ; and this without 
any extraordinary nicety in the construction 
of the machine.” 
Mr. Robins then gives an account of the 
machine by which he measures the velocities 
of the balls, which machine is simply this; 
viz. a pendulous block of wood suspended, 
freely by a horizontal axis, against which 
block ai e to be tired tiie balls whose veloci- 
ties are to be determined. 
“ This instrument thus fitted, if the weight 
of tiie pendulum is known, and likewise the 
respective distances ot its centre of gravity, 
and ot its centre of oscillation, from its axis 
of suspension, it will thence be known what 
motion will be communicated to this pendu- 
lum by the percussion of a body of a known 
weight moving with a known degree of ce- 
lerity, antr striking it in a given point; that 
is, it the pendulum is supposed at rest before 
the percussion, it will be known what vi- 
bi at ion it ougiit to make in consequence of’ 
such a determined blow; and, on the con- * 
trary, it the pendulum, being at rest, is 
struck by a body of a known weight and 
the vibration which the pendulum makes 
after the blow is known, the velocity of the 
striking body may thence be determined 
“ Fience then" if a bullet of a known 
weight strikes the pendulum, and the vi- 
bration which the pendulum makes in con- 
sequence of the stroke is ascertained the 
velocity with which the ball moved is thence 
to lie known. 
Mr. Robins then explains his method of 
computing velocities from experiments with 
this machine ; which method is rather trou- 
blesome and perplexed, as well as the rules 
ot Lulu and Antoni^ who followed him in 
