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Pjftol-barrels are forged in one piece, and are cut 
afunder at the muzzles after they have been bored ; by . 
which there is not only a faving of iron and of labour, 
but a certainty of the caliber being perfedtly the fame 
in both. 
The next operation confifts in giving to the barrel 
its proper caliber ; this is termed boring. The boring- 
bit is a rod of iron,' fomewhat longer than the barrel ; 
one end being made to fit the foclcet of the crank, and 
the other being furnifhed with a cylindrical plug of 
tempered fteel, about an inch and a half in length, and 
having its furface cut in tlte manner of a perpetual 
fcrew, the threads being flat, about a quarter of an 
inch in breadth, and running with very little obliquity. 
This form gives the bit a very, ffrong hold of tire metal; 
and the threads, being fharp at the edges, fcoop out 
and remove every roughhefs, and inequality from the 
- infide of the barrel, and render the cavity fimooth and 
equal throughout. A number of bits, each a little 
larger than the preceding one,' are afterwards fuccef- 
fiv'ely, palled through the barrel in the fame way, until 
it has acquired the intended caliber. The equality of 
the bore is fo eflential to the excellence of a piece, that 
the greateft accuracy in every other particular will not 
compenfate for the want of it. Any perfon who withes 
to know the merit of his piece in this refpedl, may do 
it with tolerable accuracy, by means of a plug of lead, 
call on a rod of iron or wood ; or even by a mufket- 
ball, filed fo as to fit the bore exactly, and pufhed 
through the barrel by the ram-rod, care being taken 
not to ufe an iron ^am-rod, or much force, left the ball 
be flattened, arid an artificial difficulty created. 
The barrel may now be confidered as quite finithed, 
with regard to its infide ; at Jeaft it has nothing more 
to be done to it by the maker. The gunfmiths, how¬ 
ever, generally make it undergo a farther operation of 
polithing, after which it is in a condition to receive its 
proper form and proportions externally, by means' of 
the file. To do this with accuracy, four flat fides or 
faces are fir ft formed ; then eight, then fixteen ; and fo 
on, until it is made quite round ; except the reinforced 
part, which in moft of the modern fowling-pieces is left 
with eight fides. This odtagonal form of the rein¬ 
forced part is certainly more elegant than the round one 
formerly in ufe. But it adds to the weight of the bar¬ 
rel, without increafing.its ftrength ; for the effort of the 
powder will always be fuftained by the thinneft part of 
the circumference, without any regard to thofe places 
that are thicker than the reft. 
It is abfolutely neceflary to the foundnefsof a barrel, 
that it fliould be of an equal thicknefs on every fide ; 
or, in the ianguage of the workmen, a barrel ought to 
be perfectly upright. In order to arrive, as nearly as 
po,ffible, to this perfect equality, the gunfmiths employ 
an iniirument which they call a compafs. It confifts of 
an iron rod bent, fo as to form two parallel branches, 
about an inch diftant from each other. One of thefe 
branches is introduced into the barrel, and kept clofely 
applied to the fide by means of one or more fp rings 
.with which it is furnifhed : the. other branch defeends 
parallel to this, ot} the outfide, and has feveral ferews 
palling through it, with their points ire died to the 
barrel. By fere wing thefe until their points touch the 
furface of the barrel, and then Turning the inftrument 
round within the bore, it is feen where the metal is too 
thick, and how much it rauli be' reduced ip order to 
render every part of the barrekperfeCtly equal through¬ 
out its circumference. To form the fcrew in the breech- 
end of the barrel, the firft tool employed is a plug of 
tempered fteel - , fomewhat conical, and having upon its 
furface the threads of a male fcrew. This tool, which 
istermed a ferevv-tap, being introduced info, the barrel, 
is turned from left to right, and back again, until it has 
marked out the three or four firft threads of the fcrew : 
N. 
another lefs conical tap is then introduced ; and, when 
this has carried on the impreflion of the fcrew as far as 
it is intended to g,o, a third tap is employed, which is 
nearly cylindrical, and fcarcely differs from the plug of 
the breech which is intended to fill the fcrew thus 
formed in the barrel, ffhe breech-plug has its fcrew 
formed by means of a i'crew-plate made of tempered 
fieel, and has feveral female ferews correfponding with 
the taps employed to form that in tire barrel. A plug- 
of feven or eight threads is fufficiently long; and the 
threads ought to be neat and fharp, fo as to fill com¬ 
pletely the turns made in the barrel by tlie tap. The 
breech-plug is afterwards cafe-hardened, or has its fur¬ 
face converted into ;fteel, by being covered over with 
fhavings of horn, or parings of horfe-hoof, and kept 
red-hot in the fire for fome time, after which it is 
plunged into water. 
The lafi operation in fowling-pieces is that of colour¬ 
ing the barrel; previous to which it is polifhed with 
fine emery and oil, until it prefents to the eye, through¬ 
out its whole length, and in whatever direction we ob- 
ferve it, a perfectly fmooth, equal, and fplendid, fu*- 
face. Formerly thefe barrels were coloured by expof- 
ing them to a degree of heat which produced ail elegant 
blue, tinge; but, as this effect arifes from a degree of 
calcination taking place upon the.furface of the metal, 
the infide of the barrel always fuffered . by. undergoing" 
the fame change. This, therefore, added to the painful 
fenfation excited in the eye, by looking along a barrel 
fo coloured, has caufed the practice of blueing to be 
difufed for fome time paft. Infield of it, barrels are 
now browned for all fowling-pieces. To do this, the 
barrel is rubbed over with aqua-fortis, or fpirit of fait, 
diluted with water, and laid afide until a complete coat 
of ruft is formed upon it; a little oil is then applied ; 
and the furface, being rubbed dry, is polifhed by me;ans 
of a hard br'ufh and bees-wax. 
When the barrels intended for a double-barrelled 
piece are drefled to their proper thicknefs, which is ge¬ 
nerally lefs than for fingle barrels, each of them is filed 
flat on the fide where it is to 'join the other, fo that 
they may fit clofely together. Two; correfponding 
notches are then made at the muzzle and breec h of each 
barrel; and into thefe are fitted two fmall pieces of 
iron, to hold them more ftrongly together. The bar¬ 
rels being united by tinning Hie parts where they touch., 
the ribs are fitted in, and made^faft by the fame means. 
Thefe ribs are the triangular pieces of iron which are 
placed between -the barrels, running on the upper and 
under fides their whole length, and lerving to hold 
them more firmly together. The under rib is a late, 
improvement, and is found more effectually to prevent 
the barrels from warping. When the.barrels are thus 
joined, they are polilhed and coloured in the manner, 
already Sefcribed. 
The tzoijled barrel fowling-pieces are defervedly ce¬ 
lebrated for their fuperior elegance and ftrength, as well 
.as for the accuracy with which they throw either ball 
or fliot. The iron employed in them is formed of flubs*, 
which are old horfe-fhoe nails, procured from country 
farriers, and from poor people who gain a .fiubfj.ftence 
by picking them up on the great roads leading to the 
metropolis. Thefe are originally fp ; r ( med ; .from.tjieToft- 
eft arid'tougheft iron that can be had ; and, the metp.l is 
iiili farther purified by the numerous heatings and ham¬ 
merings it has undergone in being reduced fro.m a bay 
into the fize and form of nails. They coft abqut. ten 
firillings the hundred-weight, and, twenty-,eight pounds 
are required to make a fingle barrel of the ordinary, 
fize. A hoop of i,r r oa about an.irich broad, and fix or 
feven inches diameter* is placed perpendicularly ; and. 
the flubs, previoufly' freed from dirt by wafhing, are 
iieatly piled in it, with .their heads putermoft on 
each fide, until tlie hoop is quite filled and wedged tight 
