PLU 



PLU 



and over Ibis lay a very fine linen cloth. In 

 this process great regard is had to the 

 just degree of heat, so as that the lead may 

 run well, and yet not burn 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 casting Pipes ivitlmut 

 snldeiing. 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 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-randies, one at each end of 

 the mould, which they serve to close ; 

 and to these is joined a little copper- 

 tube, about two inches lo-ng, 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 1 

 for rundle, &c. at the other end. Thing's 

 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 plum- 

 bers 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. 



PLUME, a set or btinrh 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 general colour or mixture of the 

 feathers of a hawk, wlych shows her 

 constitution. 



PLUMERIA, in botany, so named in 



honour of Charles Plumier ; a g.cnujs t> 

 the Pentandria Monogynia class and or- 

 der. Natural order of Contortse. Apo- 

 cinex, Jussieu. Essential character: con- 

 torted ; follicles two, reflex ; seeds insert- 

 ed into their proper membrane. There 

 are four species. 



PLUMMET, PIATMB HUT.E, or PLUMH- 

 I.IXK, an instrument used by carpenters, 

 masons, &c. in order to judge whether 

 walls, &c. be upright planes, horizontal, 

 or the like. It is thus culled from a piece 

 of lead, " plumbum," fastened to the end 

 of a cord, which usually constitutes this 

 instrument. Sometimes the string de- 

 scends along a wooden ruler, &c. raised 

 perpendicularly on another ; in which 

 case it becomes a level. See LKVEL. 



PLUM MING, among miners, is the 

 method 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 hap- 

 pens in it. It is performed in this man- 

 ner : a skilful person, with an assistant, 

 and with pen, ink, and paper, and a long 

 line, and a sun-dial, after his guess of the 

 place above ground, 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 further 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 then letting 

 down the dial again, he there likewise 

 notes down that point at which the nee- 

 dle stands in this second position. In this 

 manner he proceeds from turning to 

 turning, marking 1 down the points, and 

 marking the line, till he c ; omes to the 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 s.uch 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 em- 

 bryo plant within the seed, which as- 

 cends and becomes the stem or trunk. It. 

 extends itself into the cavity of the lobes, 

 and is terminated by a small branch re- 

 sembling a feather, from which it derive^ 

 its name, 





