444 LON 
<to the melting of the gold and filver, but to lifting in 
and out the pots containing the precious metals, with 
fafety, eafe, and expedition. The filver is melted in pots 
of calt-iron, but the gold is melted in fmaller pots raa- 
.nufaftured from black-lead, or carburet of iron. The 
.filver is run into plates ten inches long, feven wide, and 
about five-eighths of an inch thick ; the gold plates are 
-ten inchts in length, four in breadth, and three eighths 
of an inch in thicknefs. While the metal is pouring into the 
moulds, there are three portions taken, from the top, the 
middle, and bottom, of each pot, and carried to the king’s 
afTay-office, there to be examined by the matter of that of¬ 
fice, and not permitted to pafs into work uctil the finenefs 
of the metal is accurately determined. The furnaces ufed 
«re air-furnaces; and the fuel is coke. In the procefs of 
melting there will necefiarily be watte; every thing, there¬ 
fore, that can poffibly contain any portion of the precious 
metals, fuch as the (weepings of the melting-houfe, &c. 
are collected and carried to another apartment, in which 
are erefted two grinding and two triturating mills, where 
the fweep is worked up, and the fine metals in part re¬ 
covered, in the manner prafififed by refiners and gold¬ 
smiths. The fweep, thus brought together, is ground 
into a powder, and patted through a fine iieve, by which 
the larger grains of metal are obtained. The fweep is 
then put, in fmall portions, into a wooden bowl with two 
iron handles, and carefully wafhed ; the lighter particles, 
being abforbed by the water, are collefled in a large tub ; 
the heavy or metallic ones are found depofited at the bot¬ 
tom of the bowl. By thefe means the moft confiderable 
,of the particles of gold and filver are obtained. The pow¬ 
dered fweepings, however, which have been collected af¬ 
ter the walhing procefs, ftill contain portions of metal; to 
obtain thefe, the fweep, in certain portions, is put into a 
mill containing generally about a hundred-weight of mer- 
ptiry, the remainder of the mill being filled with water. 
This is commonly called the triturating-mill ; and each charge 
Is agitated about four hours with an iron inftrument, hav¬ 
ing four arms placed horizontally, in the thape of a crofs, 
.and fixed to the centre of the mill; and, for the better agi¬ 
tation of the fweep and mercury, the motion of this mill 
can be reverfed at pleafure. 
From the melting-houfe, the plates above deferibed, 
provided they are found by the aflay-niafter to be of the 
exaft degree of finenefs, are carried to the rolling-mill. 
They are firtt hot-rolled, that is, made red-hot in a furnace 
adapted-to the purpofe, and then patted through a pair of 
ratt-iron rollers. In the room in which this operation is 
performed there are four pair of rollers, which (as they 
require an immenfe power) are put in motion by a fteam- 
engine of a power equal to that of thirty horfes. The 
rollers are placed very near the furnaces; and the metal, 
being brought to what is called a blood-red heat, is taken 
out by a man w ith a pair of fmith’s tongs, and immediately 
returned by another man, and again patted through while 
hot two or three times, by which it is greatly extended;' 
after this, it is annealed. This procefs is called the break¬ 
ing-down rolling ; and, when finiflied, the plates of filver 
are about -j^ths of an inch thick. They are then cut into 
flips by a pair of circular (hears attached to the (hafts by 
yvhich the rollers are worked ; after which they are finiflied 
in what are called the adjujling-rollers, which are alfo made 
pf catt-iron, and very finely polifiied. In this procefs the 
flips are rolled cold ; and, when a piece cut from the mid¬ 
dle of each is found of the proper ftandard weight, they 
are carried to another apartment, called the cutting-out 
room, containing twelve machines worked by a (team-en¬ 
gine of the power of (ixteen horfes. With thefe machines 
Jhe blank pieces are cut out from the (trips or lamina; juft 
mentioned with great eafe and velocity. The only ma¬ 
nual labour required, is that performed by a boy nine or 
ten years old at each machine ; he quickly learns the art 
&f prefenting the laminae to the cutters, which inttantly 
cut out the blank pieces of metal; thefe fo (truck fall 
£.lirpu£h a hole that condu&s to a box placed below to re- 
D O N. 
ceive them. Each machine will cut 60 pieces in a mi¬ 
nute, of courl'e twelve will produce 720 in a minute, or 
43,200 in an hour. Formerly thefe machines were worked 
by hand by a man or boy at each cutter, but no manual 
labour can operate fo accurately and well as the power ob¬ 
tained by the fteam-engine. The inftruments with which 
the blanks are cut (called a bed and punch) are made of lteel, 
of the exatt diameter of the piece of money required. From 
this apartment the blanks are carried to th e adjujling-room, 
where every piece is moft accurately weighed, the gold twice 
at leaft, and the filver once ; thofe pieces that are found 
too heavy are reduced by the file called a float-, and thofe 
that are found too light, which occafionally occurs, are re¬ 
melted. The blanks, now properly adjufted, are carried 
to the milling-room. But the procefs of milling is a fecret 
by the very conftitution of the mint. This has always 
been the cafe (Ince the time of Peter Blondeau, who in¬ 
troduced the milling in 1662, as appears from an extrafl 
from Mr. Folkes, in his Tables of Engliih Silver Coins, in 
which he obferves, and the obfervation holds good even 
now, though at the diftance of fixty-nine years; that “it 
may be noted, that this praftice of keeping fecret the man¬ 
ner of edging the money is ftill obferved in our mint, all 
thofe who are entrnfted with it being fworn not to difeo- 
ver it; notwithftanding, the manner in which the fame 
operation is performed in feveral foreign mints is there 
publicly (hown.” The blanks, when milled, are annealed 
or foftened, in order that they may be fitted to receive the 
impreftion. 
The next operations are pickling and cleaning. The 
procefs of pickling is to throw the pieces of gold, thus 
annealed, into a Itrong folution of fuper-fulphat of alu- 
mine, thofe of filver into a folution of the fuper-fulphat 
of potafh. When the pieces are properly blanched, they 
are taken into another room to be dried and cleaned ; which, 
operation is performed by agitation in fieves, containing 
faw-dult, over a gentle heat. They are now taken to what 
is properly called the coining-room. In this apartment 
there are eight coining-prett'es, worked by a ten-horfe 
power fteam-engine; the apartment alfo is, in the winter 
months, heated with fleam, fo as to be kept to an uniform 
temperature. The machines are worked with the molt 
perfeft accuracy, and with fuch rapidity, that each will 
produce about 60 in a minute; and on the average, allow¬ 
ing for the necettary delays in working, forty pieces of 
money, that is 320 guineas, &c. will pafs through, the 
eight machines in a minute, or about 19,200 in an hour. 
Thefe machines require alfo one boy of ten or twelve 
years of age to each, who, by fupplying the machine with 
the planchets, runs no rifque of injury to his fingers, 'as 
the machine contains in itfelf a felf-feeder or layer-on ; the 
bufinefs of the boy being only to fill the layer-on, through a 
tube, with the blanks. From this tube, the machine places 
the blanks upon the dye; and, when ftruck, difplaces 
one piece and replaces another; and fo on, as long as the 
fteam-engine is kept at work.— The coin thus completed 
is carried to the mint-office, where the king’s aflayer at¬ 
tends, and where the procefs called pixing takes place, t@ 
afeertain the weight and finenefs of the moneys before de¬ 
livery. The pix is a box in which a fmall proportion or 
fample of the coins ftruck at the mint is referved, in order 
to be allayed and compared with a check-piece or ftandard 
kept in the exchequer for the purpofe. This operation, 
which is called pixing, or the trial of the pix, is performed 
with great exaftnefs, in the prefence of the privy-council,, 
the officers of the mint, and a jury of the goldfmiths’ com¬ 
pany ; and there is no inftance upon rscord of the coins 
thus tried being found to vary from the full ftandard. 
The officers of the mint are, 1. The warden, who is the 
chief, and is to receive the bullion, and overfee all the 
other officers. This officer has under him a deputy and 
two clerks. 2. The mafter-worker, with three clerks; he 
receives the bullion from the warden, caufes it to be melted, 
and delivered to the moneyers 5 and takes it from them again 
when coined. 3. The comptrojler, with a deputy and 
jclerk, 
