PLUMBERY

PLUMBERY, the art of casting and working
lead, and using it in building.

As this metal melts soon and with little heat, it is
easy to cast it into figures of any kind, by running it
into moulds of brass, clay, plaster, &c. But the

chief article in plumbery is sheets and pipes of lead; Plumbery.
and as these make the basis of the plumber's work, we
shall here give the process of making them.

In casting street-lead, a table or mould is made use of,
which consists of large pieces of wood well jointed, and
bound with bars of iron at the ends; on the sides of
which runs a frame consisting of a ledge or border of
wood, three inches thick, and four inches high from
the mould, called the sharps: the ordinary width of
the mould, within these sharps, is from four to five
feet; and its length is 16, 17, or 18 feet. This
should be something longer than the sheets are in-
tended to be, in order that the end where the metal
runs off from the mould may be cut off, because it is
commonly thin, or uneven, or ragged at the end.
It must stand very even or level in breadth, and some-
thing falling from the end in which the metal is pour-
ed in, viz. about an inch, or an inch and a half, in
the length of 16 or 17 feet or more, according to the
thinness of the sheets wanted; for the thinner the sheet,
the more declivity the mould should have. At the
upper end of the mould stands the pan, which is a
concave triangular prism, composed 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 sheets are cast; it stands with its bottom,
which is a sharp edge, on a form at the end of the
mould, leaning with one side against it; and on the
opposite side is a handle to lift it up by, to pour out
the melted lead; and on that side of the pan next the
mould, are two iron-hooks to take hold of the mould,
and prevent the pan from slipping while the melted
lead is pouring out of it into the mould. This pan is
lined on the inside with moistened sand, to prevent it
from being fired by the hot metal. The mould is also
spread over, about two inches thick, with sand sifted
and moistened, which is rendered perfectly level by
moving over it a piece of wood called a strike, and
smoothing it over with a smoothing plane, which is a
plate of polished brass, about one-fourth of an inch
thick, and nine inches square, turned up on all the
four edges, and with a handle fitted on to the upper or
concave side. The sand being thus smoothed, it is
fit for casting sheets of lead: but if they would cast a
cistern, they measure out the bigness of the four sides;
and having taken the dimensions of the front or fore-
part, make mouldings by pressing long slips of wood,
which contain the same mouldings, into the level sand;
and form the figures of birds, beasts, &c. by pressing
in the same manner leaden figures upon it, and then
taking them off, and at the same time smoothing the
surface where any of the sand is raised up by making
these impressions upon it. The rest of the operation
is the same in casting either cisterns or plain sheets of
lead: but before we proceed to mention the manner
in which that is performed, it will be necessary to
give a more particular description of the strike. The
strike, then, is a piece of board about five inches broad,
and something longer than the breadth of the mould
on the inside; and at each end is cut a notch, about
two inches deep, so that when it is used, it rides up-
on the sharps with those notches. Before they begin
to cast, the strike is made ready by tacking on two
pieces of an old hat on the notches, or by slipping a
cane

Plumbery. case of leather over each end, in order to raise the under side about one-eighth of an inch, or something more, above the sand, according as they would have the sheet to be in thickness; then they tallow the under edge of the strike, and lay it across the mould. The lead being melted, it is put into the pan with ladles, in which, when there is a sufficient quantity for the present purpose, the scum of the metal is swept off with a piece of board to the edge of the pan, letting it settle on the sand, 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 much be regulated according to the thickness of the sheets wanted, and is known by its beginning to stand with a shell or wall on the sand round the pan, two men take the pan by the handle, or else one of them lift it by the bar and chain fixed to a beam in the ceiling, and pour it into the mould, while another man stands ready with the strike, and, as soon as they have done pouring in the metal, puts on the mould, sweeps the lead forward, and draws the overplus into a trough prepared to receive it. The sheets being thus cast, nothing remains but to roll them up, or cut them into any measure wanted: but if it be a cistern, it is bent into four sides, so that the two ends may join the back, where they are soldered together; after which the bottom is soldered up.

The method of casting pipes without soldering. To make these pipes they have a kind of little mill, with arms or levers to turn it withal. The moulds are of brass, and consist of two pieces, which open and shut by means of hooks and hinges, their inward caliber or diameter being according to the size of the pipe, usually two feet and a half. In the middle is placed a core or round piece of brass or iron, somewhat longer than the mould, and of the thickness of the inward diameter of the pipe. This core is passed through two copper rundles, one at each end of the mould, which they serve to close; and to these is joined a little copper tube about two inches long, and of the thickness the leaden pipe is intended to be of. By means of these tubes, the core is retained in the middle of the cavity of the mould. The core being in the mould, with the rundles at its two ends, and the lead melted in the furnace, they take it up in a ladle, and pour it into the mould by a little aperture at one end, made in the form of a funnel. When the mould is full, they pass a hook into the end of the core, and, turning the mill, draw it out; and then opening the mould, take out the pipe. If they desire to have the pipe lengthened, they put one end of it in the lower end of the mould, and pass the end of the core into it; then shut the mould again, and apply its rundle and tube as before, the pipe just cast serving for rundle, &c. at the other end. Things being thus replaced, they pour in fresh metal, and repeat the operation till they have got a pipe of the length required.

For making pipes of sheet-lead, the plumbers have wooden cylinders, of the length and thickness required; and on these they form their pipes by wrapping the sheet around them, and soldering up the edges all along them.