GUN 
GUN 
*90 
any, especially in the low-priced barrels. 
"Hie reason of a barrel’s bursting from an in- 
equality in the bore is, that the elastic fluid, 
set loose by the inflammation of the powder, 
and endeavouring to expand itself in every 
direction, being repelled by the stronger 
parts, acts with additional force against the 
weaker ones, and frequently bursts through 
them, which it would not have done had the 
sides been equally thick and strong through- 
out. With regard to defects arising from the 
bad quality of the iron, it is impossible to say 
any thing certain. As the choice of tire ma- 
terials depepds entirely on the gunsmith, the 
only way to be assured, of having a barrel 
made of proper metal is to purchase it from 
an artist of known reputation, and to give a 
liberal price for the piece. 
The recoil of a piece becomes an object of 
importance only when it is very great; for 
every piece recoils in some degree when it is 
discharged. The most frequent cause of an 
excessive recoil is an inequality in the bore 
of the barrel ; and by this it will be occasion- 
ed even when the inequality is too small to 
be perceived by the eye. The explanation 
of this upon mechanical principles in- 
deed is not very easy : for as it is an in- 
variable law, that action and reaction are 
equal to one another, we should be apt to 
suppose that every time a piece is discharged 
it should recoil with the whole difference be- 
tween the velocity of the bullet' and' that of 
the inflamed powder. The cause to which 
too great a recoil in muskets has been usually 
attributed, is the placing of the touch-hole at 
some distance from the breech-plug ; so that 
the powder is tired about the middle, or to- 
wards its fore part, rather than at its base. 
To avoid this some artists form a groove or 
channel in the breech-plug as deep as the se- 
cond or third turn of the screw; the touch- 
hole opening into this channel, and thus firing 
the powder at its very lowest part. It ap- 
pears, however, from a number of experi- 
ments made upon this subject by M. le Clerc, 
that it made very little difference with regard 
to the recoil, whether the touch-hole was 
close to the breech, or an inch distant from 
it. The only circumstance to be attended to 
with respect to its situation therefore is, that 
it be not quite close to the breech-plug ; as 
in such a case it is found to be more apt to 
be choked up than when placed about a quar- 
ter of an men from it. 
The only other circumstance now to be 
determined with regard to musket-barrels is 
their proper length. Formerly it was sup- 
posed that the longer they were made, the 
greater would be the distance to which they 
carried the shot, and that without any limita- 
tion. This opinion continued to prevail till 
about half a century ago, when it was first 
proposed as a doubt whether long barrels 
carried farther than short ones. With regard 
to camion, indeed, it had long before this 
time been known that they might be made 
too long ; and Balthazar Killar, a celebrated 
cannon-founder in the reign of Louis XIV. 
was able to account for it. When asked by 
Mons. Suriry de St. Remy, why theculverin 
of Nancy, which is 22 feet long, did not 
carry a ball equally fyr with a shorter piece, 
he replied, that “ the powder, when inflam- 
ed, ought to quit the cavity of the piece in a 
certain time, in order to exert its whole force 
wpou the bullet; by a longer stay part of the 
force is lost ; and the same cause may pro- 
duce an inequality in the shots, by giving 
a variation to the bullet, so as to destroy its 
rectilineal course, and throw it to one side or 
other of the mark.” Mr. Robins informs 
us, that “ if a musket-barrel, ofihe common 
length and bore, is fired with a leaden bullet 
and half its weight of powder, and if the 
same barrel is afterwards shortened one-half, 
and tired with the same charge, the velocity 
ot the bullet in this shortened barrel will be 
about one-sixth less than what it was when 
the barrel was entire ; and if, instead of short- 
ening the barrel, it is increased to twice its 
usual length, when it will be near eight feet 
long, the velocity of the bullet will not be 
augmented more than one-eighth part. And 
the greater the length of the barrel is in pro- 
portion to the diameter of the bullet, and the 
Smaller the quantity of powder, the more in- 
considerable will these alterations of velocity 
be.” From these considerations it appears, 
that the advantages gained by long barrels 
are by no means equivalent to the disadvan- 
tages arising from the weight and incum- 
brance of using them ; and from a multitude 
ot experiments it is now apparent, that any 
one may choose what length he pleases, with- 
out any sensible detriment to the range of his 
piece, lire most approved lengths are from 
30 to 3d inches. 
An opinion has generally prevailed among 
sportsmen, that by some unknown manoeuvre 
the gunsmith is able to make a piece, loaded 
with small shot, throw the contents so close 
together, that even at the distance of 40 or 
50 paces the whole will be confined within 
the breadth of a hat. From such experi- 
ments as have been made on this subject, 
however, it appears, that the closeness or 
wideness with which a piece throws its shot is 
liable to innumerable variations from causes 
which no skill in the gunsmith can possibly 
reach. So variable are these causes, that 
there is no possibility of making the same 
piece throw its shot equally close twice suc- 
cessively. In general, however, the closer 
the wadding is, the better disposed the shot 
seems to be to fall within a small compass. 
In firing with small shot a curious circum- 
stance sometimes occurs, viz. that the grains, 
instead of being equally distributed over the 
space they strike, are thrown in clusters of 
10, 12, 15, or more; whilst several consi- 
derable spaces are left without a grain in 
them. Sometimes one-third or one-half of 
the charge will be collected into a cluster of 
this kind; nay, sometimes, though much 
more rarely, the whole charge will be col- 
lected into one mass, so as to pierce a board 
near an inch thick at the distance of 40 or 
45 paces. Small barrels are said to be more 
liable to this clustering than large ones ; and 
M. de Marolles informs us, that this is espe- 
cially the case when the barrels are new, and 
likewise when they are fresh-washed ; though 
he acknowledges that it did not always hap- 
pen with the barrels he employed even after 
they were washed. It is probable, therefore, 
that the closeness of the shot depends on some 
circumstance relative to the wadding rather 
than to the mechanism of the barrel. 
Gun-shot wounds are attended with 
much worse consequences than wounds made 
by sharp instruments ; for the parts are more 
shattered and torn, especially when the shot 
G U N 
falls upon the joints, bones, or any consider- 
able part. See Surgery. 
GUNTER’S Chain, the chain in com- 
mon use for measuring land, according to the 
true or statute measure ; so called from Mr. 
Gunter, its reputed inventor. 
The length of the chain is 66 feet, or 22 
yards, or four poles of five yards and a half 
each ; and it is divided into 100 links, of 7.92 
inches each. 
This chain is the most convenient of any 
thing for measuring land, because the con- 
tents thence computed are so easily turned 
into acres. The reason of which is,* that an 
acre of land is just equal to 10 square chains, 
or 10 chains in length and one in breadth, or 
equal to 100,000 square links. Hence the 
dimensions being taken in chains, and multi- 
plied together, it gives the content in square 
chains ; which therefore being divided by 10, 
or a figure cut off for decimals, brings the 
content to acres : alter which the decimals 
are reduced to roods and perches, by multi- 
plying by 4 and 40. But the better way is to 
set the dimensions down in links as integers, 
considering each chain as 100 links; then, 
having multiplied the dimensions together* 
producing square links, divide these by 
100,000 that is, cut off' five places for deci- 
mals, the rest are acres, and the decimals are 
reduced to roods and perches as before. 
Ex. Suppose, in measuring a rectangular 
piece of ground, its length be 
795 links, 
and its breadth 480 links. 
63600 
3180 
Ac. 3.81600 
4 
Ro. 3,264 
4v5 
Per. 10.560 
So the content is 3 acres 3 roods 1.0 perches, 
Gunter’s line, a logarithmic, line, usu- 
ally graduated upon scales, sectors, &c. 
It is also called the line of lines, and line 
of numbers; being only the logarithms gra- 
duated upon a ruler, which therefore serves 
to solve problems instrumentally in the same 
manner as logarithms do arithmetically. It 
is usually divided into a hundred parts, every 
tenth ot which is numbered, beginning with 
1, and ending with 10; so that if the first 
great division, marked 1, stand for one-tenth 
of any integer, the next division, marked 2 
will stand for two-tenths ; 3, three-tenths, 
and so 011 ; and the intermediate divisions 
will, in like manner, represent 100th parts of 
some integer. If each of the great divisions, 
represent 10 integers, then will the lesser di- 
visions stand for integers ; and if the great di- 
visions be supposed each 100, the subdivi- 
sions will be each 10. 
use of gunter’s line. 
1. To find, the produet ofi two numbers. 
From 1 extend the compasses to the multi- 
plier ; and the same extent, applied the same 
way from the multiplicand, wail reach to the 
product. Thus il the product of 4, and & be 
required, extend the compasses from 1 to 4 
and that extent laid from 8 the same wav, 
will reach to 32, their product. 
