g t; n 
G V & 
6SQ GUN 
this business : but a much simpler rule is given 
in Dr. Hutton’s Tracts, vol. i. p. 119, where 
the experiments are explained at full length, 
and this rule is expressed by either of the two 
following formulas : 
v i= 5-6727 eg x o ~ 6l4*58«- X , 
bir birii 
the velocity; where v denotes the velocity 
of the ball when it strikes the pendulum, p 
the weight of .the pendulum, b the weight of 
the ball, c the chord of the arc described by 
the vibration to the radius r, g the distance 
below the axis of motion to the centre of 
gravity, o the distance to the centre of oscil- 
lation, i the distance to the point of impact, 
and n the number of oscillations the pendu- 
lum will perform in one minute, when made 
to oscillate in small arcs. The latter of these 
two theorems is much the easiest, both be- 
cause it is free of radicals, and because the 
value of the radical o, in the former, is to 
be first computed from the number a - , or 
number of oscillations the pendulum is ob- 
served to make. $*, 
Soon after the first publication of Robins’s 
New Principles of Gunnery, in 1742, the 
learned in several other nations, treading in 
his steps, repeated and farther extended the 
same subject, sometimes varying and enlar- 
ging the machinery ; particularly Euler in 
Germany, D’Antoni in Italy, and Messrs. 
D’Arcy and Le Roy in France : but most 
of these, like Mr. Robins, with small fire- 
arms, such as muskets and fusils. 
Rut in the year 1775, in conjunction With 
several able officers of the Royal Artillery, 
and other ingenious gentlemen, Dr. Hutton 
Undertook a course of experiments with the 
ballistic pendulum, in which the machinery 
was extended to cannon-shot of 1,2, and 3 
pounds weight. An account of these ex- 
periments was published in the Philos. Trans, 
for 1778, “and for which,” says the Dr., “the 
Royal Society honoured me with the prize 
of the gold medal. These were the only ex- 
periments that I know of which had been 
made with cannon-balls for this purpose, 
although the conclusions to be deduced from 
such, are of the greatest importance to those 
parts of natural philosophy which are depen- 
dant on the effects of fired gunpowder ; nor 
do 1 know of any other practical method of 
ascertaining the initial velocities within any 
tolerable degree of t lie truth. The know- 
ledge of this velocity is of the utmost conse- 
quence in gunnery ; by means of it, together 
with the law of the resistance of the medium, 
every thing is determinable relative to that 
business ; for, besides its being an excellent 
method of trying the strength of different 
sorts of powder, it gives us the law relative 
to the different quantities of powder, to the 
different weights of shot, and to the different 
lengths and sizes of guns. Besides these, 
there does not seem to be any thing wanting 
to answer any inquiry that can be made con- 
cerning the flight anil ranges of shot, except 
the effects arising from the resistance of the 
medium. In these experiments the weights 
of the pendulums employed were from 300 to 
near 600 pounds.” In that paper is described 
the method of constructing the machinery, of 
finding the centres of gravity and oscillation 
of the pendulum, and of making the experi- 
ments, which are all set dowyi in the form of 
a journal, with all the minute and concomi- 
tant circumstances ; as also the investigation 
| of the new and easy rule, set clown just above, 
for computing the velocity of tiie ball from, 
the experiments. The charges of powder 
were varied from 2 to 8 ounces, and the shot 
from 1 to near 3 pounds. And from the 
whoie were cleariv deduced these principal 
inferences: viz. 
“ 1. First, That gunpowder fires almost 
instantaneously. 2. That the velocities com- 
municated to balls or shot, of the same 
weight, by different quantities of powder, are 
nearly in the subduplicate ratio of those quan- 
tities ; a small variation, in defect, taking 
place when the quantities of powder became 
■great. 3. And when shot of different weights 
are employed, with the same quantity of 
powder, the velocities communicated to them 
are nearly in the reciprocal subdoplicatc- 
ratio of their weights. 4. So that, univer- 
sally, shot which are of different weights, and 
impelled by the firing of different quantities 
of powder, acquire velocities which are di- 
rectly as the square roots of the quantities 
of powder, and inversely as the square roots 
of the weights of the shot, nearly. 5. It 
would therefore be a great improvement in 
artillery, to make use of shot of a long form, 
or of heavier matter ; for thus the momentum 
of a shot, when fired with the same weight of 
powder, would be increased in the ratio of 
the square root of the weight of the shot. 
6. It would also be an improvement to di- 
minish the windage ; for by so doing, one- 
third or -more of the quantity of powder 
might be saved. 7. When the improve- 
ments mentioned in the last two articles are 
considered as both taking place, it is evident 
that about half the quantity of powder might 
be saved, which is a very considerable ob- 
ject. But important as this saving may be, 
it seems to be still exceeded by that of the 
article of the guns ; for thus a small gun may 
be made to have the effect and execution ot 
another of two or three times its size in the 
present mode, by discharging a shot of two 
or three times the weight of its natural ball or 
round shot. And thus a small ship might 
discharge shot as heavy as those of the 
greatest now made use of. 
“ Finally, as the above experiments ex- 
hibit the regulations with regard to the 
weights of powder and balls, w hen fired from 
the same piece of ordnance, &c. ; so by mak- 
ing similar experiments with a gun, varied 
in its length, by cutting off from it a certain 
part before each course of experiments, the 
effects and general rules for the different 
lengths of guns may be certainly determined 
by them. In short, the principles on which 
these experiments were made, are so fruitful 
in consequences, that, in conjunction with 
the effects resulting from the resistance of 
the medium, they seem to be sufficient for 
answering all the enquiries of the speculative 
philosopher, as well as those of the practical 
artillerist.” 
GUNPOWDER, a composition of nitre, 
sulphur, and charcoal, mixed together, and 
usually granulated. 
It appears that Roger Bacon knew of gun- 
powder. Fie tells us, in his Treatise De Se- 
cretis Operibus Artis & Naturae, & de Nulii- 
tate Magi a:, cap. 6, which is supposed bv 
some to have been published at Oxford in 
1216, “ that from saltpetre and other ingredi- 
ents, u r e are able to make a lire that shall 
burn at what distance we please.” And Dr. 
Plott, in his History of Oxfordshire, p. 236, 
assures Its that these “ other ingredients 
were explained in a MS. copy of the same: 
treatise, in the hands of Dr. G. Langbaifi, 
and seen by Dr. Wallis, to be sulphur and 
wood-coa!.” 
As to the preparation of gunpowder, there 
are various compositions of it, with respect 
to the proportions of the three ingredients, 
to be met with in pvrotechnical writings ; 
but the process of making it up is much the 
same in all. 
For some time after the invention of artil- 
lery, gunpowder w as of a much weaker com- 
position than that now in use. But when 
guns of modern structure were introduced, 
gunpowder of the same composition as the 
present came also into use. In the time of 
Tartaglia the cannon-powder was made of 
4 parts of nitre, one of sulphur, and one of 
charcoal: and the musket-powder of 48 parts 
oi nitre, 7 parts of sulphur, and 8 parts of 
charcoal; or ot 18 parts of nitre, 2 parts of 
sulphur, and 3 parts of charcoal ; the mo- 
dern composition is, 
76 parts nitre 
15 charcoal 
9 sulphur 
100 . 
These ingredients are first reduced to St 
fine powder separately, then mixed intimate- 
ly, and formed into a thick paste with water. 
After this has dried a little, it is placed upon 
a kind of sieve full of small holes, through 
which it is forced. By that process it is di- 
vided into grains, the size of which depends 
upon the size of the holes through which they 
have been squeezed. The pow’der, when 
dry, is put into barrelj, which are made to 
turn round on their axes. By this motion 
the grains of gunpowder rub against each 
other, their asperities are worn off, , and their 
surfaces are made smooth. The powder is 
then said to be glazed. 
Gunpowder, as is well known, explodes 
violently when a red heat is applied to it. 
This combustion takes place even in a va- 
cuum ; a vast quantity of gas is emitted, the 
sudden production of which is the cause of 
all the violent effects which this substance 
produces. Their combustion is evidently 
owing to th.e decomposition of the nitre by 
the charcoal and sulphur. The products are 
carbonic acid gas, azotic gas, sulphurous 
acid gas, and probably sulpliureted hydro- 
gen. Mr. Cruikshank* has ascertained that 
no perceptible quantity of water is formed. 
What remains after the combustion is potass 
combined with a small portion of carbonic 
acid, sulphat ot potass, a very small propor- 
tion of su Ip hu ret of potass, and unconsumed 
charcoal. This mixture soon attracts mois- 
ture, and the sulphuret .which it contains 
enables it to act strongly on metallic bodies. 
To make gunpowder duly, regard is to be 
had to the purity or goodness of the ingredi- 
. ents, as wel 1 as the proportions of them ; 
for the strength of the powder depends much 
on that circumstance, and also on the due 
working or mixing of them together. 
To purify the nitre, bv taking away the 
lixt or common salt, and" earthy part. Dis- 
solve it in a quantity of hot writer over the 
tire ; then filtrate it through a tlannel hag, 
Into an open vessel, and set it aside to cool, 
and to crystallize. These crystals may in 
like manner be dissolved and crystallized 
again ; and so on, till they become quite pure 
