Wire, a small metallic rod or thread, varying in thickness from half an inch to 1/5000 of an inch. The facility with which a metal may be drawn into wire is called its ductility. (See Ductility.) From an examination of the history of wire drawing, Beckmann is led to conclude that in early times metals were brought to the filamentous form only by beating into thin plates, then dividing these into narrow strips, and finally rounding with the hammer and file. Such a view agrees with the account given in Exod. xxxix. of the sacerdotal dress, and with that of the fable of Vulcan's forging a net of delicate wirework with which to ensnare Mars and Venus. The earliest known mention of " wire drawers " and " wire millers," as those who produced wire by drawing were variously called, occurs in 1351 and 1360, in the histories respectively of Augsburg and Nuremberg, the previous accounts being only of "wire smiths," or those who fabricated wire with the hammer. The change from the old to the new method was accomplished, or very soon followed, by the introduction of a machine, probably the invention of one Ludolf of Nuremberg, by which wire was produced without direct aid of the hand. The precious metals appear to have been the first subjected to this process.

White wire, or blanch iron wire, is in fact mentioned in a list of articles not to be imported into England in 1463; and in 1484 both iron and latten (fine brass) wire are similarly named. Anderson, however, records that up to 1565 English iron wire was drawn by hand only, and was so poor that most of that used in the country, and also wool cards and other articles involving the employment of wire, were imported; and that in the year named patents were granted to certain Dutchmen or Germans to manufacture wire in England. In 1630 this manufacture is spoken of as employing many thousand persons, and producing a superior article; and the importation of foreign wire, wool cards, and hooks and eyes, of the last named of which (made from wire) a very large amount was already consumed, was again formally prohibited. In the 17th century the business of wire drawing became largely established about Barnsley in Yorkshire; while the manufacture of copper and brass wire also was begun (1649) by foreigners at Esher. - For wire, the best and toughest wrought iron is selected. Formerly this was prepared for drawing by hammering it out into convenient rods of nearly a half inch thickness.

These rods were then extended and further reduced by a sort of coarse drawing, called ripping or rumpling, by means of a machine, believed to be also the invention of Ludolf, in which a pair of pincers were made to advance to the draw-plate, seize the protruding end of the rod, and then, being moved back and drawing the metal thus far, to relax their hold, advance again to the plate, and repeat the process. Owing to the interrupted action, the use of this machine involved loss of time, while a degree of unevenness in the product, and the marks left by the pincers, rendered it unsuitable for the manufacture of small wire or that of the best quality. Until recently, however, and especially on the continent of Europe, iron wire was drawn altogether by such a machine. At present, iron, and usually steel, are prepared for the final drawing by passing between grooved rollers very accurately made and adjusted, of 7 or 8 in. diameter, and sometimes making 350 revolutions to the minute. The cast-steel wire for the best needles and some similar articles is prepared for drawing with the hammer, in preference to submitting it to the rolling process.

But however the metal may be prepared, and in whatever manner the drawing may be performed, this latter operation is in all cases essentially the same in principle. Very commonly the draw-plate is a piece of hardened or shear steel, about 6 in. long and 1½ in. thick, flattened on one side and slightly tapered toward the ends. From the flat side of this plate, at which they have their larger extremity, to the opposite side, several conical holes are pierced, their smaller orifices being carefully finished to the sizes they are respectively intended to give to the wire drawn through them. As the holes necessarily become enlarged by long use, when this occurs the smaller orifices are reduced by hammering, and then opened to the proper size again by means of a long taper needle, called a pritchell. The French draw-plates, it appears, are formed by repeatedly fusing and hammering, to insure their complete union, the two lateral parts of a compound bar, one part being of wrought iron, the other part of a sort of steel, called potin, previously obtained by melting to a paste fragments of cast-iron pots with whitewood charcoal, throwing this into cold water, and repeating the melting and sudden cooling 10 or 12 times.

When the union of the two parts is complete, the plate is reheated and extended; and it is then several times heated and punched with successively smaller punches, to secure tapering holes; though these, which are of course smallest at the steel or hardest side, are left to be finished in the cold plate by the wire drawer himself. The orifices should be made successively smaller by almost imperceptible gradations, so that the reduction of the wire and the effort required shall be at the successive drawings as nearly uniform as possible. - Whether wire is drawn by machinery or by hand, after a few drawings, and less in number as its size is smaller, it so far becomes brittle under the process as to be in danger of snapping off, or at least as to impair its quality and strength; and it requires to be annealed. (See Annealing.) The wire is then scoured or washed to free it from oxide; immersion for a time in starch water or in stale beer grounds is found to favor this result. At a wire manufactory some years since, some ingots of brass were heated and quenched in the slightly acid liquor employed for cleaning the annealed wire, as a ready means of warming the liquor; this wire was found to pass with unusual ease through the draw-plate; and an examination showed that the acidulated liquor had deposited over the wire (by galvanic action) a delicate film of copper, which appeared then to play the part of lubricant to the iron.

This has led to the employment ever since in that factory of a weak solution of a copper salt in the cleaning liquor, the copper film being wholly removed in connection with the last annealing. With most descriptions of wire, grease also is commonly and freely used, and with the finer sizes wax, for lubrication. - Mr. Brockedon in 1819 patented the use in fine draw-plates of the hardest precious stones. With a plate having a hole pierced through a ruby, of 0.0033 in. in diameter, a silver wire 170 m. long has been drawn so nearly uniform that neither the micrometer nor the weighing of equal lengths at the two ends showed any difference in the size. In 1813 Dr. Wollaston communicated to the royal society a method devised by him for preparing wires of extreme tenuity, for use in place of the "spider lines" in the telescope. He drilled holes lengthwise through small rods of silver, cast into these cores of gold, drew the compound bars, and then removed the silver by an acid. Subsequently he drew platinum wire, say to 1/100 inch diameter, and cast about this a cylinder of silver, such that the platinum should be 1/20 the diameter of the compound rod; this rod, 1/5 in. in diameter, is then drawn to a wire so fine that, the two metals (as in case of the gold and silver above) perfectly maintaining their relative diameters throughout the process, the removal of the silver by nitric acid leaves a platinum wire of far less size than could be attained by drawing the metal singly, which has been brought, it is said, to a thickness of Only 1/30,000 of an inch.

Of such wire, a mile's length would weigh but a grain, and 150 filaments in close contact would barely equal the size of an ordinary filament of raw silk. Actual gold wire being in use for a few purposes only, among them that of making filigree work, that which is commonly known as "gold wire" is really silver gilt; and the mode of making this quite as strikingly exemplifies the extreme ductility of the precious metals. A silver rod an inch in diameter is covered with leaf gold, and by drawing and annealing this rod is then reduced to the finest wire required; and though in the outset but 100 to 140 grains of gold are thus allowed to a pound of silver, the wire produced is still completely coated. Such wire is wound upon thread to form gold thread, the economy as well as beauty of the product being increased by previously flattening the wire between polished steel rollers. Brass wire also is made so fine, even by the ordinary processes, that gauze may be woven from it which shall have 67,000 meshes to the square inch. - Wire is applied to a great variety of uses, among which is that of the manufacture of wire gauze or cloth. Beckmann refers to some very intricate and curious old specimens of wire network.

The plainer sorts of wire gauze or network are woven on looms differing but little from those for cloth. Those of large wire and open meshes are employed for fences, large cages or buildings of wire for birds or small animals, and for coarse riddles or sieves, etc.; the finer sorts are put to use in the construction of sieves, lanterns, flour-dressing machines, paper-making machinery, screens for windows, safety lamps, etc. By pressing sheets of wire gauze in moulds, the shape of which they retain, and finishing off their edges with hoops or rings, these are formed into dish covers, baskets, etc. The wire in bird cages, fenders, and other like articles is often specially plaited or woven in forming them, so that, as in the case of the making of baskets, they admit of a great variety of construction and ornamentation. Knitting and sewing needles and pins are at first cut from wire expressly prepared for such manufacture, and some of the finest sorts of steel wire are consumed in making the hair springs of timepieces. A very important use of steel, wire is its application in the way of the so-called "strings" of pianos.

Spangles, or paillettes, which are small flat disks of metal with an opening in the centre, and used for ornamenting garments, are formed of wire, by twisting this spirally round a rod, cutting so as to obtain as many single coils or rings, and then flattening these with a hammer upon a smooth anvil. Gold and silver wires are much used in the production of filigree work. (See Filigree.) Wire is also used in making "wire concrete." This is done by stretching on a metal framework a system of wires or wire cordage, and enclosingit in concrete. Doors and shelves can be formed in this way, and it is proposed to utilize the invention in the construction of sea walls. - For the making of wire into wire rope, and in reference to the comparative strength and some of the uses of such rope, see Bridge, and Rope; and for the use of wire in telegraph lines, see Telegraph. Brass wire is used in large quantities for the manufacture of pins and of hooks and eyes; also for binding the handles of brooms. Copper and sometimes iron wire is used for the same purposes. Wire is also often used in the manufacture of fences.

Its chief advantage is that sections or panels of fence may be formed in framework, which may be joined and fastened together in such lengths as occasion may require, and readily moved.