Popular Technology Volume II Part 19

18. Clocks and watches are constructed on the same general principles.

The mechanism of both is composed of wheel-work, with contrivances to put it in motion, and to regulate its movements. The moving or maintaining power in large clocks is a weight suspended by a cord to a cylinder. In watches, and sometimes in small clocks, this office is performed by a steel spring. In the clock, the regulation of the machinery is effected by the pendulum, and in the watch, by the balance-wheel, or spring balance. In either case, the maintaining power is prevented from expending itself, except in measured portions.

19. The time is indicated by hands, or pointers, which move on the dial plate. The minute hand is attached to the axle of the wheel which makes its revolution in sixty minutes, and the hour hand to the one which makes the revolution in twelve hours. Greater and smaller divisions of time are kept and indicated on the same principle. The part of a clock which keeps the time, is called the going part; and that which strikes the hour, the striking part.

20. The division of labor is particularly conspicuous in the manufacture of watches, as the production of almost every part is the labor of a distinct artisan. The workman who polishes the several parts, and puts them together, is called, among this cla.s.s of tradesmen, the _finisher_ or _watch-maker_. Those, therefore, who deal largely in watches in England, purchase the different parts from the several manufacturers, and cause them to be put together by the finisher.

21. Watches are extensively manufactured in various parts of Europe, but particularly in French Switzerland, France, and England. The London watchmakers have been celebrated for good workmanship, for more than a century and a half. This manufacture has not yet been commenced in the United States, although the machinery, or _inside work_, is very often imported in tin boxes, and afterwards supplied with dial plates and cases. This is especially the case with the more valuable kinds of watches.

22. Bra.s.s clocks are manufactured in most of our cities, and in many of our villages, and wooden clocks, in great numbers, in the state of Connecticut. These last are carried by pedlers into the remotest parts of the country, so that almost every farmer in our land can divide the day by the oscillations of the pendulum.

[Ill.u.s.tration: COPPERSMITH.]

THE COPPERSMITH, THE b.u.t.tON-MAKER, AND THE PIN-MAKER.

COPPER.

1. Copper is a ductile and malleable metal, of a pale yellowish red color. It is sometimes found in a native state, but not in great quant.i.ties. The copper of commerce is princ.i.p.ally extracted from the ores called sulphurets. Copper mines are wrought in many countries; but those of Sweden are said to furnish the purest copper of commerce, although those of the island of Anglesea are said to be the richest.

2. In working sulphureted ore, it is first broken into pieces, and roasted with a moderate heat in a kiln, to free it from sulphur. When the ore is also largely combined with a.r.s.enic, a greater degree of heat is necessary. In such a case, it is spread upon a large floor of a reverberatory furnace, and exposed to a greater heat. By this treatment, the sulphur and a.r.s.enic are soon driven off.

3. The ore is then transferred to the fusing furnace, and smelted in contact with fuel. The specific gravity of the copper, causes it to sink beneath the _scoria_ into a receptacle at the bottom of the furnace. To render the metal sufficiently pure, it requires repeated fusions, and, even after these, it usually contains a little lead, and a small portion of antimony.

4. _Alloys of copper._--Copper is combined by fusion with a great number of metals, and, in such combinations, it is of great importance in the arts. When added in small quant.i.ties to gold and silver, it increases their hardness, without materially injuring their color, or diminishing their malleability. An alloy, called white copper, imported from China, and denominated, in that country, _pakfong_, is composed of copper, zinc, nickel, and iron. It is very tough and malleable, and is easily cast, hammered, and polished. When well manufactured, it is very white, and as little liable to oxydation as silver.

5. Copper, with about one-fourth of its weight of lead, forms _pot-metal_. _Bra.s.s_ is an alloy of copper and zinc. The proportion of the latter metal varies from one-eighth to one-fourth. Mixtures, chiefly of these two metals, are also employed to form a variety of gold-colored alloys, among which are _prince's metal_, _pinchbeck_, _tombac_, and _bath-metal_.

6. A series of alloys is formed by a combination of tin and copper.

They are all more or less brittle, rigid, and sonorous, according to the relative proportions of the two metals; these qualities increasing with the amount of tin. The princ.i.p.al of these alloys are, _bronze_, employed in the casting of statues; _gun-metal_, of which pieces of artillery are made; _bell-metal_, of which bells are made; and _speculum-metal_, which is used for the mirrors of reflecting telescopes.

7. The alloys of copper were very prevalent among the nations of antiquity, and were used, in many cases where iron would have answered a much better purpose. The instruments of husbandry and of war, as well as those for domestic uses generally, were usually made of bronze, a composition which furnishes the best subst.i.tute for iron and steel. The Corinthian bra.s.s, so celebrated in antiquity, was a mixture of copper, gold, and silver.

8. The earliest information of the use of this metal by mankind, is found in the fourth chapter of Genesis, in which it is stated, that "Tubal-Cain was the instructer of every artificer in bra.s.s and iron."

This individual was the seventh generation from Adam, and was born about the year of the world 500.

THE COPPERSMITH.

1. Copper, being easily wrought, is applied to many useful purposes.

It is formed into sheets by heating it in a furnace, and compressing it between steel rollers. The operation of rolling it const.i.tutes a distinct business, and is performed in mills erected for the express purpose.

2. The rolled sheets are purchased according to weight by the coppersmith, who employs them in sheathing the bottoms of ships, in covering the roofs of houses, and in constructing steam-boilers and stills. He also fabricates them into a variety of household utensils, although the use of this metal in preparing and preserving food, is attended with some danger, on account of the poisonous quality of the verdigris which is produced on the surface.

3. An attempt has been made to obviate this difficulty, by lining the vessels with a thin coating of tin. This answers the purpose fully, so long as the covering of tin remains entire. But, in cases of exposure to heat, it is liable to be melted off, unless it is kept covered with water.

4. This metal can be reduced by forging to any shape; but, during the process, it will bear no heat greater than a red heat; and, as it does not admit of welding, like iron, different pieces are united with bolts, or rivets, of the same metal, as in the case of the larger kinds of vessels, or by means of solder made of bra.s.s and zinc, or zinc and lead, as in the case of those of smaller dimensions.

5. Bra.s.s is applied to a greater variety of purposes in the arts than copper. This preference has arisen from its superior beauty, from the greater facility with which it can be formed into any required shape, and from its being less influenced by exposure to the ordinary chemical agents.

6. Some of the articles manufactured of bra.s.s, are forged to the required form, and others are made of rolled sheets; but, in most cases, they pa.s.s through the hands of the bra.s.s-founder, who liquifies the metal, and pours it into moulds of sand. For the sake of lightness, and economy of material, many articles are made hollow; in such cases, they are cast in halves or pieces, and these are afterwards soldered together.

7. Pieces which have been cast are generally reduced in size, and brought more exactly to the proposed form, either in a lathe, with tools adapted to turning, or in the vice, with files and other suitable instruments. The operators in bra.s.s form a cla.s.s of mechanics distinct from those who work in copper.

THE b.u.t.tON-MAKER.

1. Trifling as the manufacture of b.u.t.tons may appear, there are few which include a greater variety of operations. The number of substances of which they are made is very great, among which are gold, silver, various alloys of copper, steel, tin, gla.s.s, mother-of-pearl, bone, horn, and tortoise-sh.e.l.l, besides those which consist of moulds of wood or bone, covered with silk, mohair, or similar materials.

2. In making gilt b.u.t.tons, the _blanks_, or bodies, are cut from rolled plates of bra.s.s, with a circular punch driven by means of a fly wheel. The blanks thus produced, are planished with a plain die, if they are intended for plain b.u.t.tons; or with one having on it an engraved figure, if they are to be of the ornamental kind. In either case, the die is usually driven with a fly press.

3. The shanks are next placed on one side of the proposed b.u.t.ton, and held there temporarily with a wire clasp. A small quant.i.ty of solder and rosin having been applied to each shank, the b.u.t.tons are exposed to heat on an iron plate, until the solder shall have melted. The shanks having been thus firmly soldered on, the b.u.t.tons are turned off smoothly on their edges in a lathe.

4. The b.u.t.tons are next freed from oxyde, by immersing them in diluted nitric acid, and by friction in a lathe. They are then put into a vessel containing a quant.i.ty of nitric acid supersaturated with mercury. The superior attraction of the copper for the acid, causes a portion of it to be absorbed; and the mercury held in solution by it, is deposited on the b.u.t.tons, which are next put into a vessel containing an amalgam of mercury and gold.

5. The amalgam is formed by melting the two metals together, and afterwards pouring them into cold water. The composition having been put into a bag of chamois leather, and a part of the mercury pressed through the pores, the remaining portion is left in a condition approaching the consistency of b.u.t.ter, and in a fit state for use.

Before the b.u.t.tons are put into the amalgam, a small quant.i.ty of nitric acid is added.

6. The b.u.t.tons having been covered with the amalgam, as before stated, the mercury is discharged, that the gold may adhere directly to the bra.s.s. This object is effected by heating the b.u.t.tons in an iron pan, until the amalgam begins to melt, when they are thrown into a large felt cap, and stirred with a brush. This operation is repeated several times, until all the mercury has been volatilized. The whole process is finished by again burnishing them, and putting them on cards for sale.

7. White metal b.u.t.tons are made of bra.s.s alloyed with different proportions of tin. They are cast, ten or twelve dozens at a time, in moulds formed in sand, by means of a pattern. The shanks are placed in the centre of the moulds, so that, when the metal is poured in, they become a part of the b.u.t.tons. The b.u.t.tons are next polished in a lathe, with grindstone dust and oil, rotten stone and crocus martis.

They are then boiled with a quant.i.ty of grained tin, in a solution of crude red tartar or argol, and lastly, finished with finely-pulverized crocus, applied with buff leather.

8. Gla.s.s b.u.t.tons are made of various colors, in imitation of the opal and other precious stones. While manufacturing them, the gla.s.s is kept in a state of fusion, and a portion of it for each b.u.t.ton is nipped off out of the crucible with a metallic mould, somewhat similar to that used for running bullets, the workman having previously inserted into it the shank.

THE PIN-MAKER.

1. There is scarcely any commodity cheaper than pins, and none which pa.s.ses through the hands of a greater number of workmen in the manufacture, twenty-five persons being successively employed upon the material, before it appears in these useful articles, ready for sale.

2. The wire having been reduced to the required size, is cut into pieces long enough to make six pins. These pieces are brought to a point at each end by holding them, a handful at a time, on a grindstone. This part of the operation is performed with great rapidity, as a boy twelve years of age can sharpen 16,000 in an hour.

When the wires have been thus pointed, the length of a pin is taken off at each end, by another hand. The grinding and cutting off are repeated, until the whole length has been used up.

3. The next operation is that of forming the heads, or, as the pin-makers term it, _head-spinning_. This is done with a _spinning-wheel_, by which one piece of wire is wound upon another, the former, by this means, being formed into a spiral coil similar to that of the springs formerly used in elastic suspenders. The coiled wire is cut into suitable portions with the shears, every two turns of it being designed for one head. These heads are fastened to the _lengths_ by means of a hammer, which is put in motion with the foot, while the hands are employed in taking up, adjusting, and placing the parts upon the anvil.

4. The pins are now finished, as to their form; but still they are merely bra.s.s. To give them the requisite whiteness, they are thrown into a copper vessel, containing a solution of tin and the lees of wine. After a while, the tin leaves the liquid, and fastens on the pins, which, when taken out, a.s.sume a white appearance. They are next polished by agitating them with a quant.i.ty of bran in a vessel moved in a rotary manner. The bran is separated from them, as chaff is separated from wheat.

5. Pins are also made of iron wire, and colored black by a varnish composed of linseed oil and lamp-black. This kind is designed for persons in mourning. Pins are likewise made with a head at each end, to be used by females in adjusting the hair for the night, without the danger of p.r.i.c.king. Several machines have been invented for this manufacture, one of which makes a solid head from the body of the pin itself; but the method just described still continues to be the prevailing one.

6. Pins are made of various sizes. The smallest are called minikins, the next, short whites. The larger kinds are numbered from three to twenty, each size increasing one half from three to five, one from five to fourteen, and two from fourteen to twenty. They are put up in papers, according to their numbers, as we usually see them, or in papers containing all sizes. In the latter case, they are sold by weight.

7. It is difficult, or even impossible, to trace the origin of this useful little article. It is probable, however, that it was invented in France, in the fifteenth century. One of the prohibitions of a statute, relating to the pin-makers of Paris of the sixteenth century, forbid any manufacturer to open more than one shop for the sale of his wares, except on new-year's day, and on the day previous.

8. Hence we may infer, that it was customary to give pins as new-year's presents, or that it was the usual practice to make the chief purchases at this time. At length it became a practice, in many parts of Europe, for the husband to allow to his wife a sum of money for this purpose. We see here the origin of the phrase, _pin-money_, which is now applied to designate the sum allowed to the wife for her personal expenses generally.

9. Prior to the year 1443, the art of making pins from bra.s.s wire was not known in England. Until that period, they were made of bone, ivory, or box-wood. Bra.s.s pins are first mentioned in the English statute book, in 1483, when those of foreign manufacture were prohibited.