WIRE. 



foot to a length of two feet, and give it the form it is to 

 have. It is well known that caft iron cannot be worked 

 at the forge without breaking under the hammer ; but in 

 the prefent inftance, it is alloyed with the iron-bar, and is 

 drawn out with it. It has alfo acquired new properties by 

 the repeated fufions with charcoal. 



The holes are next pierced whilft the plate is hot. This 

 is done with a well-pointed punch of German fteel, applied 

 on that fide of the plate which is the iron-bar. It requires 

 four heats in the fire to pierce the holes, and every turn a 

 finer punch is employed, fo as to make a taper hole. The 

 makers of draw-plates do not pierce the holes quite through, 

 but leave it to the wire-drawers to do it themfelves when 

 the plate is cold, with Iharp punches, and then they open 

 the hole to the fize they defire ; and although this potin is 

 of a very hard fubftance, the fize of the hole may be re- 

 duced by gentle blows with a hard hammer, on the flat fur- 

 face of the plate, round the hole. 



A great many holes are made in the fame plate ; and it 

 is important that they (hould diminiih in fize by very im- 

 perceptible gradations ; fo that the workman can always 

 choofe a hole fuitablc for the wire he is to draw, without 

 being obliged to reduce it too much at once. 



To afcertain the fize of the wire, gauges are ufed. They 

 are commonly made of a piece of wire bent in zigzag, as 

 (hewn in^^. 1 1 ; and the fpace between every bend is of a 

 different width ; but a better fort is made of a fteel-plate, 

 with notches on the edge. ( Seejg. 12. for the ftandards. ) 

 Thefe {hould be hardened, that they may not be fubjeft to 

 wear. 



Fig. 13. is another kind of gauge, which is very accurate. 

 It confifts of two ftraight rules of fteel, put together at an 

 angle. The diameter of the wire is indicated by the depth 

 to which it will enter into the angle ; the edges of the 

 rulers are divided into equal parts for that purpofe, and 

 cumbered, to correfpond with the different fizes of wire. 



The wire manufaftory of MefFrs. Mouchel, fituated at 

 I'Aigle, in the department de I'Orne, is one of the moft 

 confiderable in France. It furnifhes annually, in cards for 

 wool-combing only, an hundred thoufand quintals of iron- 

 wire, each loolbs. A part of this is confumed in France, 

 and the reft is exported to Portugal, Spain, Italy, and even 

 to the fiiores of the Levant. 



They employ the iron manufaftured in the departments 

 of rOrne and La Haute Saone, as being of the beft qua- 

 lity. The firft produces the beft wire for making fcrews, 

 nails, and pins, as much on account of its hardnefs as its 

 fine pohfh, which refembles fteel-wire. In this relpeft, it is 

 fuperior to the iron of Haute Saone, but from its duflihty 

 the latter can now be made extremely fine, and it appears to 

 be moft free from heterogeneous particles. 



The fmelted iron, prepared and hammered, being in a ftate 

 nearly fit for their purpofe, is tranfported, at a fmall ex- 

 pence, to I'Aigle, by the rivers and canals. They have a 

 forge to reduce the fteel and iron of Normandy, which 

 arrives in large pieces, into fmall and regular bars. 



When the iron is formed into an irregular bar of about 

 a centimetre, near four-tenths of an inch in diameter, they 

 begin to draw it into wire. Although it be already 

 much extended by hammering, it is in the firft place pafied 

 four times through the drawing-plate ; then its molecules 

 become difpofed lengthways, and exhibit fibres at their 

 utmoft extenfion. The fibres muft be removed by means 

 of heat, which difperfes and divides them ; and after that 

 the wire may again be reduced three numbers. The fibres 

 which are re-produced by this operation are again removed 

 by heat. The whole procefs is five times repeated ; confe- 

 8 



quently the wire is pafled through fifteen numbers ; aftez 

 which, a fingle expofure to the fire is fufficient to fit it for 

 paffing fix others, whereby it is reduced to the thicknefs o( 

 a knitting-needle. 



The fteel-wire, being much harder, requires to be pafled 

 through forty-four numbers, and to be annealed every othei 

 time. 



The machine which draws the fteel-wire muft go flowei 

 than that which draws the iron ; for the firft being verj 

 hard, and offering more refiftance to the drawing-plate, 

 fhould be pulled out with more care, fince the quickneft 

 ought to be proportioned to the refiftance, and reciprocally; 

 and if they depart from this principle, the refults will vary 

 Thus, for example, the iron of the department de I'Orne, 

 which is more compaft than that produced at Haute Saone, 

 if drawn by the fame machines, augments in hardnefs, and 

 is weakened when it is brought to too great a degree of 

 finenefs. But this iron, which is very hard, and capable of 

 receiving a very high polilh, is to be preferred for certain 

 ufes. 



In order to anneal the wire, they formerly employed a 

 large and elevated furnace, with bars of caft iron to fupport 

 the wire in the middle of the flames. It contains feven 

 thoufand pounds weight, fo contrived as to contain equal 

 portions of each number. They are fo arranged that the 

 thickeil wires receive the ftrongeft heat ; therefore, the whole 

 is equally heated in the fame fpace of time. The operation 

 lafts three hours with a fire well kept up, and it might be 

 imagined that this apparatus was completely adapted to the 

 purpofe ; but there are imperfeftions in this method, be- 

 caufe it leaves the wire expofed to the contaft of the at- 

 mofpheric air, the oxygen of which feizes it with extreme 

 avidity; whence a confiderable quantity of oxyd is occa. 

 fioned, and alfo an operation to free it from the fcales, 

 which confifts of beating the bundles of wire with a wooden; 

 hammer wetted with water. 



Notwithftanding this precaution, there often remains 8, 

 portion of oxyd adhering to the furface of the metal, whicb' 

 ftreaks the draw-plate, or fixes on the wire, and gives it : 

 tarnifhed appearance, and caufes it to break when it ii 

 brought to a great degree of finenefs. This furnace is only 

 ufed for the fteel-wire, or the iron from I'Orne, which is 

 lefs liable to change, and befides being harder is not fc 

 ealily attacked by the oxygen. 



In order to diminifti the waf^e that the fire occafions. 

 they have contrived another procefs, which confifts in dip. 

 ping the bundles of wire into a bafin of wet clay before 

 they put them into the furnace ; and they are left in tk 

 furnace to dry before the fire is lighted, without which pre- 

 caution the clay would peel off" from the iron. 



For making wire for cards, M. Mouchel invented anothei 

 furnace. It is round, and about one metre fix decimetres it 

 diameter, and one metre eight decimetres in height, without 

 including its parabolic arch and the chimney above it. Th( 

 interior is divided by horizontal grates into three ftories ; tht 

 loweft receives the cinders, the fecond is the fire-place, anc 

 into the third or upper place they Hide a roleau of wire, weigh- 

 ing one hundred and fifty kilogrammes, which is inclofec 

 in a fpace compriled between two caft-iron cylinders, beinj 

 luted to prevent the admiflion of air between them. Tb( 

 flames circulate about the outfide of the firft, and withii 

 the interior of the fecond, which defends the wire from at- 

 mofpheric air. The diameter of the largeft cylinder ii 

 about one metre four decimetres, that of the fecond oni 

 metre. Thus the fpace comprifed between them is two de- 

 cimetres, on an elevation of five decimetres. There muf 

 be feveral pairs of cylinders provided ; becaufe whilft om 



pai 



