Gold wire

“ It fuses at 1090°—at a higher temperature than silver—and can be drawn into exceedingly fine wires or hammered into thin sheets. With its softness and ductility, gold is distinguished for its tenacity, and a gold wire two millimetres thick breaks only under a load of 68 kilograms. Gold vaporises even at a furnace heat, and imparts a greenish colour to a flame passing over it in a furnace. ”

“ It is old, too, but until a new demon of material ambition began to stir in crowding populations it had little purpose except to adorn the raiment of the great or add richness to ancient arts. People whose vision of man’s past is bounded by the encyclopedia have been told times enough that Aaron’s robe had gold wire threads in it, that there was wire in the pyramids, that Nineveh was beating out wire eight hundred years before the tragedy of Calvary, and that metal heads with hair of wire were found in the ruins of Herculaneum and are now again entombed in the showcases of the Portici Museum. ”

“ Next, we find a dozen workwomen, each at her machine, pushing snips of gold into grooves, where they are pierced with a pattern, or one or two holes of a pattern, and made to fall into a receiver below. Each may take about a second of time. Farther on, slender gold wire is twisted into links by myriads. At every seat the counter is cut out in a semicircle, whereby room is saved, and the worker has a free use of her arms. ”

“ That with their mechanical ingenuity the ancient Egyptians bethought themselves of some method for the purpose is not unlikely. From Sir Gardiner Wilkinson we learn that at Thebes were found objects which appeared to be made of gold wire. We may fairly presume that the work upon the corslets of king Amasis, already spoken of as done by the needle in gold, required by its minuteness that the metal should be not flat but in the shape of wire. ”

“ WIRE AND WIRE DRAWING It may be rather disconcerting to some enthusiastic ones who assume that we Moderns have made all the progress that is worth while to learn that so many of our supposedly new products were far antedated. In the case of wire, again, we were antedated as much as 30 centuries. The wires which were produced by the Ancients, however, were usually of the noble metals, gold and silver. They were not drawn through dies as are the wires that we know, but were hammered into shape from long, thin strips of metal. ”

“ But I mention this as an illustration of the fact that fine wire cannot be produced at one drawing, but must, so to speak, be coaxed down to the requisite degree of attenuation, even when so valuable a metal as gold is used. As a general rule, it may be taken that iron wire requires more coaxing than brass, brass more than copper, and copper more than the precious metals—their different degrees of malleability rendering them amenable to different degrees of treatment. ”

“ The physical properties requisite to make useful wire are possessed by only a limited number of metals and metallic alloys. The metals must in the first place be ductile; and, further, the wire when drawn out must possess a certain amount of tenacity, the quality on which the utility of wire principally depends. The metals suitable for wire, possessing almost equal ductility, are platinum, silver, iron, copper, aluminium and gold ”

“ Gold thread, or spun gold, is a flatted silver-gilt wire, wrapped or laid over a thread of yellow silk, by twisting with a wheel and iron bobbins. By the aid of a mechanism like the Braiding Machine, a number of threads may thus be twisted at once by one master wheel. The principal nicety consists in so regulating the movements that the successive volutions of the flatted wire on each thread may just touch one another, and form a continuous covering. The French silver for gilding is said to be alloyed with 5 or 6 pennyweights, and ours with 12 pennyweights of copper in the pound troy. ”

“ Your cares will wear away.” § 13. Gold-wire rings of three twisted wires were given away at weddings; and Anthony Wood relates of Edward Kelly, a “famous philosopher” in Queen Elizabeth’s days, that “Kelly, who was openly profuse beyond the modest limits of a sober philosopher, did give away in gold-wire rings (or rings twisted with three gold wires) at the marriage of one of his maid servants, to the value of £4,000.” [354]
[214]
§ 14. A gold ring has been discovered in Rome, which has the subject of Cupid and Psyche cut into the metal. ”

“ The head is supplied with complicated yet graceful antenna-like appendages, 49 made of wire neatly coiled and welded together by pressure or hammering. The eyes are globular and are encircled by the ends of a double loop of wire which extends along the back and incloses a line of minute balls or nodes. The peculiar wings and tail will be best understood by referring to the illustration. The foundation metal is much corroded, being dark and rotten, and the plating of reddish gold seems to have been coated with a thin film of yellow gold. ”

“ Copper is usually the only metal used to form the wire or conductor itself. The reason for this is that copper is a better conductor than any other metal except those known as precious metals, such as gold and silver, the cost of which prohibits their use for such purposes. The wire may be solid, or made up of a number of small conductors so that it is flexible. ”

“ No other company uses so much wire and hard rubber, or so many tons of brass rods, as the Western Electric. Of platinum, too, which is more expensive than gold, it uses one thousand pounds a year in the making of telephone transmitters. ”

“ Now if the ends plunged in the saline solution are terminated by platina or gold wires, no current of electricity is observed; with silver terminations, the current is very feeble; but with wires of zinc, lead, iron or tin, the current is very energetic. These remarkable effects, highly important in the phenomena hereafter to be considered, are no way connected with the conductibility of the metals; for lead and zinc, which are the worst conductors, are those which, with the copper, produce the most powerful effects. ”

“ A ring or watch case marked 14K or 18K means that fourteen or eighteen parts of it are pure gold, the balance of the twenty-four carats being some sort of alloy, copper being generally used. If articles of jewelry were made of pure gold they would not wear well, as gold is a very soft metal, and it is, therefore, necessary to mix the gold with some harder substance.
What is an Electro-Magnet?
An electro-magnet is a piece of iron temporarily converted into a magnet by means of a current of electricity sent through a wire which is coiled around it. ”

“ This is one of the very few specimens which have pure gold, or perhaps only silver-gilt wire, without any admixture of thread in it, employed in the stars and narrow oblong ornaments in the embroidery, [Pg 221] the wire itself being stitched to its grounding by thin linen thread. The large and small squares, as well as the borders, are executed in gold-twisted thread, very poor of its kind. The glittering effect of the pure metal-wire is very telling.
8582.
Piece of Silk Damask; ground, crimson; pattern, conventional peacocks and foliage, in yellow. Syrian, 13th century. ”

“ Iron seems to be the most desirable material for guard wires because it gives the required mechanical strength and sufficient conductivity at a less cost than copper, aluminum, or bronze, and is easier to handle and less liable to break than steel. It was formerly the practice to staple guard wires to the tops of poles or to the ends of cross-arms, but it was found that the wire was more apt to rust and break at the staple than elsewhere, and in the better class of work such wires are now mounted on small insulators. ”

“ Best best (B. B.) , which varies more in quality, is not so tough, and is lower in conductivity. It is frequently sold as E. B. B.;
3. Best (B.) , which is the poorest grade made, being more brittle, and lowest in conductivity. Iron wire should be well galvanized.
German Silver Wire.—German silver is an alloy consisting of 18 to 30% nickel, and the balance about four parts copper to one part zinc. It is very largely used as a resistance material in making resistance coils, and is sold in the form of wire, and strip. The resistance of this wire varies with its composition. ”

“ Shore end of cable of 1866.
Copper is one of the best conductors of electricity known, and hence the wires in the center are made of that metal. Water, too, is an excellent conductor, and if the wires were not closely protected, the electricity would pass from them into the sea, instead of carrying its message the whole length of the line. Therefore, the wires must be encased or insulated in some material that will not admit water and is not itself a conductor. Gutta-percha meets these needs, and the hemp and galvanized wire are added for the strength and protection they afford to the whole. ”

“ An ideal conductor for transmission lines should combine the best electrical conductivity, great tensile strength, a high melting point, low coefficient of expansion, hardness, and great resistance to oxidation. No one of the metals named possesses all of these properties in the highest degree, and the problem is to select the material best suited to each case. Aluminum suffers very slightly by exposure to the weather, copper and bronze suffer a little more, while iron and steel wire are attacked seriously by rust. ”

“ The piles of this equipment, waiting shipment in the Roebling storerooms, give proof that the satire of the cartoonist and the mockery of the funny writer cannot destroy an ancient faith.
The telephone and telegraph companies use uncountable miles of copper wire in line service and other miles in fine sizes for instrument coils and divers other functions. Electricity as an agent would be a halting cripple without wire. The dynamo would have little more utility than a washtub. Armatures, frames for which are formed from flat steel wire, are wound in the Roebling plant in impressive number. ”

“ CUTTING THE DIES But by and by the time comes when the wire is so fine it cuts the steel of the die and loses its rotundity. Then a harder material is needed and the wire drawer goes the whole figure and uses a diamond. Cutting the steel dies is a cunning craft enough, but the expert, who, with a hair-like drill and a dab of diamond dust can penetrate a diamond with an opening that will be regular and measure to a thousandth of an inch, is a man who would think it no trick at all to pass a well fed camel through the needle’s eye. ”

“ As the material for wire gauze and cloth, wire rope, cable, piano strings, springs of all sorts, pins, needles, nails, fence, barbed wire, and the myriad of other things, wire really is one of our great products.
It was mentioned that piano wire had been made which had a tensile strength as high as 400,000 pounds per square inch, which is six or seven times the strength of an equivalent cross-section of steel rail or plate. Wire is undoubtedly the strongest product which is made from steel. This is why wire rope or cable is so strong. ”

“ The draw-plate or die is a piece of hard cast-iron or hard steel, or for fine work it may be a diamond or ruby. The object of utilizing precious stones is to enable the dies to be used for a considerable period without losing their size, and so producing wire of incorrect diameter. Diamond dies must be rebored when they have lost their original diameter of hole, but the metal dies are brought down to size again by hammering-up the hole and then drifting it out to correct diameter with a punch. ”

“ No joint can possibly be perfect that is not metallically continuous. Careful soldering is the only certain mode of securing this, and that this is practicable is evident from the millions of perfect joints in telegraph wires. To scrape the ends of wire bright, and cover the whole with thin sheet lead, as is done by one firm, is simply to court danger. The absence of joints in wire rope is one great element in its favour.
(21) 5. Attachment to building, how made. Some attach the conductor to the building by copper straps and nails; some use holdfasts, either of copper wire or gun metal ”

“ COATING AND FINISHING Use determines much in the finishing of wire, and of wire rope as well, as not alone concerning the chemistry of the inside, but the covering of the outside. Material that is made for service out of doors, under water or under ground, to ensure long life needs an exposed surface more resistant to moisture than the naked steel. Copper is proof, but the pure wire is expensive for most uses and where severe strains are incurred it lacks in strength. Modern science has been too busy to recover the art of hardening copper which the ancient Egyptians lost. ”

“ The Material and Dimensions of the Conductor. The use of copper is almost universal, but two manufacturers occasionally use iron. The form varies. The majority use wire rope, but some use rods, others bands or tapes, others tubes. One firm uses a cable “constructed of 49 strands of hard-drawn square copper wire.” Another firm uses a wire rope, simply because “it appears to be an open question, at present, whether it is surface or mass which conducts.” ”

“ All metals are conductors, but they are not all equally good conductors. Mercury is not so good a conductor as iron, iron is not so good as copper, and silver is still a slightly better conductor than copper. The difference between the two last-named metals is, however, not great enough to justify commercially the use of silver instead of copper wire in the construction of electrical machinery. For the present we need not inquire further into any fine gradations between conductors and insulators. ”