PLU

312

PLU

Latin plumbum, lead), an artist who works in lead, and towhom is confided the pump-work, as well as the makingand forming of cisterns and reservoirs, large or small, water-closets, &c., for the purposes of domestic economy. Theplumber does not use a great variety of working tools,because the ductility of the metal upon which he operatesdoes not require them. They consist of an iron hammer,rather heavier than a carpenter’s, and with a short thickhandle ; two or three wooden mallets, of different sizes ; anda dressing and flatting tool. This last is of beech, about 18inches long and 2 -| inches square, planed smooth and flat onthe under surface, rounded on the upper, and one of its endstapered off round, as a handle. With this tool the plumberstretches out and flattens the sheet-lead, or dresses it to theshape required, using first the flat side, and then the roundone, as occasion may suit. The plumber lias also occasionfor a jack and a trying plane, similar to those of the car-penter (see Plane), with which he reduces the edges ofsheet-lead to a straight line, when the purposes to which itis to be applied require it. He should also be provided witha chalk-line, wound upon a roller, for marking out the leadinto such breadths as he may want. Ilis cutting-tools con-sist of a variety of chisels and gouges, as well as knives ; tlielatter of which are used for cutting the sheet-lead into slipsand pieces, after it has been marked out by the chalk-line.Files of different sizes are requisite for the plumber, invarious operations. In soldering, ladles of three or foursizes, for melting the solder ; and iron instruments, calledgrozing-irons, are used by the plumber. These grazing-ironsare of several sizes, and commonly about 12 inches in length,tapering at both ends, the handle-end being turned quiteround, to allow of its being firmly held while in use. Theother end is a bulb, of a spindle-shape, or sometimes spheri-cal, of a size proportioned to the soldering intended to beexecuted. They are heated to redness, when wanted foruse.

A plumber’s measuring rale is two feet in length, dividedinto three equal parts of eight inches each. Two of its legsare of box-wood, and duodecimally divided ; the third legconsists of a piece of slow-tempered steel, attached to oneof the box-legs, by a pivot, on which it turns, and falls,when not in use, into a groove cut in such leg for its recep-tion. This steel leg will pass into places that the otherscould not enter, and is also useful for occasionally removingthe oxide, or any other extraneous matter, from the surfaceof his heated metal.

Scales and weights are also necessary to the masterplumber, as he cannot charge for anything till it has beenweighed. He must also be supplied with centre-bits of allsizes, and a stock, to work them in, for the purpose of makingperforations in lead or wood, through which he may wantto insert pipes, &c. He also has occasional recourse to com-passes, to strike circular pieces of lead, to line or coverfigures of that shape. Plumbers charge their sheet-lead bythe hundred-weight.

PLUMBERY, or Plumbing, (from the Latin plumbum,lead), the art of casting and working in lead, and using it inbuilding. As this metal is very easily fusible, it is cast intofigures of any kind, with great facility, by running it inproper moulds of clay, plaster, &c., but the chief articles inplumbery are sheets and pipes of lead ; which form the basisof the plumber’s work.

Lead is obtained from the mines, and, from its being gene-rally combined with sulphur, it has been denominated asulphuret. After the ore has been taken from its bed, it issmelted, first being picked, in order to separate the unctuousand rich, or genuine ore, from the stony matrix and other

impurities ; the picked ore is then pounded under st, aoactuated by machinery, and afterwards washed to c ^ e ; j jnthe remainder of the matrix, that could not be sepa 1 p>epicking. It is next put into a reverberatory furnace j 3roasted, as the workmen call it, during whi ch °rtpl^repeatedly stirred to facilitate the evaporation ot the 3 r , e)When the surface begins to assume the appearance ot t ( i,eit is covered with charcoal, and well shaken togetn „nfire is then increased, and the purified lead flows 0 ff

run 3

fids

all sides into the basin of the furnace, whence itinto moulds prepared for its reception. The (’^-ten' 3 ’capable of receiving 1541b. of lead each ; and their cwhen cool, are called pigs in the commercial world- e tfl/The natural colour of lead is a bluish white ; 011

melted, or cut, it is very bright ; but is soon grtf

exposure to the atmosphere ; assuming first a dl otcolour, which afterwards becomes white. It is c “f‘ dr a"’ nbeing hammered into very thin plates, and may u p 0 tb etinto wire ; but its tenacity is very inferior to that paftmetals; for a leaden wire the hundred-and-twe ' 1 1 ,g.4lh'of an inch in diameter is only capable of suppo ' 11 ° f 6 mwithout breaking. Lead melts at the teniperatui e ^ # |. b 3of Fahrenheit’s thermometer ; and, if a strong^ cr ygtty'applied, it boils and evaporates. If cooled slowly ; 1 {0 it 3lizes. The change of its external colour is ° vVl „vtei' 10 'gradual combination with oxygen, which converts s ei'V 3surface into an oxide : this outward crust, however, p e, 1 f.the rest of the metal for a long time, as the air jiatev

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trate it but very slowly. Lead is not acted uponby water, though that element greatly facilitates ^p,

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ose®

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of the air upon it; for it is known, that when K a f proc e93 .to the atmosphere, and kept constantly wet, th u n<oxidation takes place much more rapidly than - g toother circumstances : hence the white crust, t . -^ct W ll|f yobserved upon the sides of leaden vessels contam^° n j Iia te 3 'just at the place where the surface of the watei ^ ^

For other particulars relative to this metal, see L t | ien iseb^

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Plumbers purchase lead in pigs, and reduce d | iee finto sheets, or pipes, as they have occasion. . _ er is

they have two kinds, cast and milled ; the f°' eS forfor covering flat roofs of buildings, laying of te ^ 1 j c b > s 'fry-ing gutters, lining reservoirs, &c.; the latter, w^. g j aS t ta^thin, for covering the hips and ridges of roots ■ ^ rea dy P ^do not manufacture themselves, but purchase 1 0 re *pared of the lead merchants, as it comes fro 111 . n

roasting furnaces. . , , ve ll

In casting sheet-lead, a copper is proviueu, n' u ^

masonry at the upper end of the workshop, '^"goai'd 3, ''j 3 .or casting-table, which consists of strong dea ^ ef 1jointed together, and bound with bars of _i r ° n ‘ . a llel°S r ‘ ]gThe sides of this table, of which the shape is a P‘^ jg to^varying in size from 4 to 6 feet in width, and o>‘

feet and upwards in length, are guarded by a j^lier tl

ing of wood, 3 inches thick, and 4 or 5 i»cl> eS ’jv

the interior surface, called the shafts ; the tab e ^ 7 ’y fl * 6firm legs, strongly framed together, about e nd ,i„ntf dlower than the top of the copper ; at the 1 PP^ j 9 3 d P^mould, nearest the copper, a box, calledin its length to the breadth of the table, bav n nJ gtala long horizontal slit, from which the hea ^ t \ie

issue, after it has been poured in from 4 rim ° u i)e / 9

box moves upon rollers along the surface 0 3 and Por-

table, and is put in motion by means °^. 10 ^ e itjngfixed to beams above. While the metal is m . nir jtface of the mould, or table, is prepared by c0 ^stratum of dry and clean sand, regularly sin0 , „f aa kind of rake, called a strike, which consi

° of w 1

othed oveOrd,i of