PLU 
of heat, so as that the lead may rim well, 
mid yet not bum the linen. This they 
judge of by a piece of paper, for it takes 
fire in the liquid lead if it is too hot, and if 
it be not shrunk and scorched a little, it is 
not hot enough. 
The Method of easting Pipes without sol- 
dering. To make the.se 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 in- 
ward calibre, or diameter, being according 
to the size of the pipe to be made, and their 
length is 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 nmdle and tube as be- 
fore, the pipe just cast .serving for rundle, 
&c. at the other end. Things being thus 
replaced, they pour in fresh metal, and re- 
peat the operation till they have got a pipe 
of the length req\iired. For making pipes 
of sheet-lead, the plumbers have wooden 
cylinders, of the length and thickness re- 
quired, and on these they form their pipes 
by wrapping the sheet around them, and 
soldering up the edges all along them. 
PLUME, a set or bunch of ostrich fea- 
thers, pulled out of the tail and wings, and 
made up to serve for ornaments in funerals, 
&c. Among sportsmen, plume is the gene- 
ral colour or mixture of the feathei s of a 
hawk, which shows her constitution. 
PLUMERIA, in botany, so named in 
honour of Charles Plumier ; a genus of tlie 
Pentandria Monogynia class and order. 
Natural order of Contortse. Apocincte, 
PLU 
Jussieu. Essential character ; contorted ; 
follicles two, reflex; seeds inserted into 
their proper membrane. There are four 
species. 
PLUMSIET, Plumb-udle, or Pi.umb- 
LiMS, an instrument nsed by carpenters, 
masons, &c. in 'order to judge whether 
walls, &e. be upright planes, horizontal, or 
the like. It is thus called from a piece of 
lead, “ plumbum,” fastened to the end of a 
cord, which usually constitutes this instru- 
ment. Sometimes the string descends 
along a wooden ruler, &c. raised perpendi- 
cularly on another ; in which case it be- 
comes a level. See Level. 
PLUMMING, among miners, is the me- 
thod of using a mine-dial, in order to know 
the exact place of the work where to sink 
down an air-shaft, or to bring an adit to 
the work, or to know which way the load 
inclines when any flexure happens in it. It 
is performed in this manner : a skilful per- 
son, with an assistant, and with pen, ink, 
and paper, and a long line, and a sun-dial, 
after his guess of the place above gror.nd, 
descends into the adit or work, and there 
fastens one end of the line to some fixed 
thing in it, then the incited needle is let to 
rest, and the exact point where it rests is 
marked with a- pen : he then goes on fur- 
ther in the line still fastened, and at the 
next flexure of the adit he makes a mark 
on the line by a knot or otherwise ; and 
tlien letting down the dial again, he there 
likewise notes down that point at which 
the needle stands in this second position. 
In this manner he proceeds from turning 
to turning, marking down the points, and 
marking the line, till he comes to tlie in- 
tended place ; this done, he ascends and 
begins to work on the surface of the earth 
what he did in the adit, bringing the first 
knot in the line to such a place where the 
mark of the place of the needle will again 
answer its pointing, and continues this till 
he comes to the desired place above ground, 
which is certain to be perpendicularly over 
the part of the mine into which the air- 
shaft is to be sunk. 
PLUMULA, in botany, a little feather, 
the scaly part of the corculum, or embryo 
plant within the seed, which ascends and 
becomes the stem or trunk. It extends it- 
self into the cavity of the lobes, and is ter- 
minated by a small branch resembling a fea- 
ther, from which it derives its name. 
PLUNGER, in mechanics, a solid brass 
cylinder, used as a forcer in forcing 
pumps. 
