705 
PLUMBERY. 
•which the metal is poured in, viz. about an inch or an 
inch and a half in the length of 20 feet, or more, according 
to the thicknefs of the fheets wanted ; for the thinner the 
{fleet, the more declivity the mould fliould have. At the 
upper end of the mould Hands the pan, which is a con¬ 
cave triangular prifm, compofed of two planks nailed 
together at right angles, and two triangular pieces fitted 
in between them at the ends. The length of this pan is 
the whole breadth of the mould in which the fheets are 
call; it Hands with its bottom, which is a fharp edge, on 
a form at the end of the mould, leaning w'ith one fide 
againflit: and on the oppofite fide is a handle to lift it 
up by, to pour out the melted lead ; and on that fide of 
the pan next the mould are two iron hooks to take hold 
of the mould, and prevent the pan from flipping while 
the melted lead is pouring out of it into the mould. 
This pan is lined on the inflde with moiflened fand, to 
prevent it from being fired by the hot metal. The mould 
is alfofpread over, about two inches thick, with fand fifted 
and moiflened, which is rendered perfectly level by mov¬ 
ing over it a piece of wood called a fir ike, and fmooth- 
ing it over with a fmoothing-plane, which is a plate of 
polifbed brafs, about one-fourth of an inch thick, and 
nine inches fquare, turned up on all the four edges, and 
with a handle fitted on to the upper or concave fide. The 
fand being thus fmoothed, it is fit for cafling fheets of 
lead : but, if they would cafl a ciflern, they meafure out 
the bignefs of the four tides; and, having taken the di- 
menfions of the front or fore-part, make mouldings by 
prefling long flips of wood, which contain the fame 
mouldings, into the level fand ; and form the figures of 
birds, beafls, &c. by prefling in the fame manner leaden 
figures upon it, and then taking them off, and at the fame 
time fmoothing the furface where any of the fand is 
raifed up by making thefe imprefiions upon it. The reft 
of the operation is the fame in cafling either cifterns or 
plain fheets of lead. But, before we proceed to mention 
the manner in which that is performed, it will be neceflary 
to give a more particular defeription of the Jlrike. The 
Itrike, then, is a piece of board about five inches broad, 
and fomething longer than the breadth of the mould on 
theinfide; and at each end is cut a notch about two 
inches deep, fo that when it is ufed it rides upon the 
fharps with thofe notches. Before they begin to cafl, the 
ftrike is made ready by tacking on two pieces of an old 
hat on the notches, or by flipping a cafe of leather over 
each end, in order to raife the under fide about one-eighth 
of an inch or fomething more above the fand, according 
as they would have the Iheet to be in thicknefs; then they 
tallow the under edge of the ftrike, and lay it acrofs the 
mould. The lead being melted, it is put into the pan 
with ladles, in which, when there is a fufficient quantity 
for the prefent purpofe, the feum of the metal is fwept 
off, with a piece of board, to the edge of the pan, letting it 
fettle on the fand, which is by this means prevented from 
falling into the mould at the pouring out of the metal. 
When the lead is cool enough, which muft be regulated 
according to the thicknels of the fheets wanted, and is 
known by its beginningto ftand with a fhell or w-all on the 
fand round the pan, two men take the pan by the handle, 
or elfe one of them lifts it by the bar and chain fixed to a 
beam in the ceiling, and pour it into the mould, while 
another man Hands ready with the ftrike, and, as foon as 
they have done pouring in the metal, puts on the mould, 
fweeps the lead forward, and draws the overplus into a 
trough prepared to receive it. The fheets being thus cafl, 
nothing remains but to roll them up, or cut them into 
any meafure wanted : but, if it be a ciflern, it is bent 
into four fides, fo that the two ends may join the back, 
where they are foldered together; after which the bottom 
is foldered up. 
When thin fheets of lead are to be cafl, the table, or 
mould, is ledged only on one fide. Inftead of fand, they 
cover it with a piece of woollen fluff, nailed down at the 
Vol. XX. No. 1403. 
two ends, to keep it tight; and over this they lay a very 
fine linen cloth. Great regard is in this procefs had to 
the lead while melting, that it have the juft degree of 
heat, fo that it may run well, yet not burn the linen. 
This they judge of by a piece of paper; for, if the paper 
take fire in the liquid lead, it is too hot; and, if it be not 
fhrunk and fcorched a little, it is not hot enough. Being 
then in its juft degree, they have a ftrike, but different 
from that deferibed in the former article ; as ferving both 
for pan and ftrike; both to contain and to condudt the 
liquid lead. It is, in effect, a wooden cafe without any 
bottom, onlyclofed on three fides. It is pretty high be¬ 
hind, but the two fides, like two acute angles, ftill dimi- 
nifh to the tip, from the place where they are joined to the 
third or middle piece, where they are of the fame height 
with it; viz. feven or eight inches high. The width of 
the middle makes that of the ftrike, which again makes 
that of the fheet to be caft. The ftrike is placed at top 
of the table, which is before covered in that part, with a 
pafteboard, that ferves as a bottom to the cafe, and pre¬ 
vents the linen from being burnt while the liquid is 
pouring in. The ftrike is fo difpofed on the table, as that 
the higheft part looks to the lower end of the table, and 
the two doping fides to the higher end. The ftrike is 
now filled with lead, according to the quantity to be 
ufed; which done, two men, one at each fide the table, 
let the ftrike defeend down the table, or elfe draw it down 
with a velocity greater or lefs, as the Iheet is to be more 
or lefs thick ; the thicknefs of the Iheet ftill depending on 
the promptitude with which the ftrike Aides down the in¬ 
clining mould. The fine frnooth {fleets of lead, thus 
made, are fometimes ufed between the joints of large 
lfones in great buildings, See. 
The lead which lines the Chinefe tea-boxes is reduced 
to a thinnefs which we are informed European plumbers 
cannot imitate. The following account of the procefs 
by which the plates are formed was communicated to a 
writer in the Gentleman’s Magazine by an intelligent 
officer of an Eaft Indiaman. “The cafter fits by a pot 
containing the melted metal; and has two large {tones, 
the under one fixed, the upper moveable, diredtly before 
him. He raifes the upper Hone by preffing his foot upon 
the fide of it, and w ith an iron ladle pours in the opening 
a proper quantity of the fluid metal. He then immedi¬ 
ately lets fall the upper ftone, and by that means forms 
the lead into a thin irregular plate, which is afterwards 
cut into a proper fitape. The furfaces of the {tones, 
where they touch each other, are exactly ground toge¬ 
ther.” 
Plumber's work is commonly eftimated by the pound or 
hundred-weight; and the weight may be difeovered by 
the meafure of it, in the manner below ftateci. Sheet- 
lead, uled in roofing, guttering, See. is commonly be¬ 
tween feven and twelve pounds weight to the iquare foot; 
but the following Tabie {hows by infpedtion the parti¬ 
cular weight of a fquare foot for each of feveral thick- 
nefles. 
Thickness. 
Pounds to a 
Square Foot. 
Thickness. 
Pounds 10 a . 
Square Foot. 
•10 
5' 8 99 
*15 
8-848 
* I I 
6-489 
•16 
9-438 
1 
9 
6‘554 
X 
6 
9-831 
•12 
7 ’° 7 S 
•17 
10-028 
T 
¥ 
7*373 
•18 
io - 6i8 
■J 3 
7-668 
•19 
I I *207 
•14 
8-258 
II 
11-797 
1 
7 
8-427 
*21 
12-387 
Required the weight of a quantity of lead which is 39 
;et 6 inches long, and 3 feet 3 inches broad, at 85 lbs. to 
ae fquare foot. „ . , 
8 R Decimals. 
