WATCH MAKER.
1. Silver is a metal of a fine white color, and, in brilliancy, inferior to none of the metals except steel. In malleability, it is next to gold, it being capable of reduction into leaves not more than the⅟160000 of an inch in thickness, and of being drawn into wire much finer than a human hair.
2. The relative value of silver and gold has varied considerably in different ages. In the prosperous period of ancient civilization, one pound of gold was worth twelve of silver. In Great Britain, the relative value of the two metals is one to fifteen and one-fifth, and, on the continent of Europe, it is about one to fifteen. In the United States, the relative value of these two metals has been recently established by Congressat one to sixteen. In China and Japan, it is said to be one to nine or ten.
3. There are two methods of separating silver from its various ores, and these are calledsmeltingandamalgamation. In the former method, the ore and a due proportion of lead are heated together; and the latter, from its great affinity for silver, unites with it, and separates it from other substances. The two metals are afterwards separated from each other, by melting them on a cupel, and then exposing them to a current of atmospheric air, by which the lead is converted into an oxyde, while the silver remains untouched. This process is calledcupellation.
4. In the other method, the first thing done is to roast the ore, to expel the sulphur and other volatile parts. It is then reduced to an impalpable powder by machinery; and having been sifted, it is agitated sixteen or eighteen hours in barrels, with a quantity of quicksilver, water, and iron, combined in certain proportions. This agitation causes the several substances composing thecharge, to unite according to their respective affinities.
5. The silver and mercury combine, forming an amalgam, which, having been put into a leather sack, a part of the latter is separated from the rest by filtration, still leaving six parts of this metal to one of the silver. The amalgam is next submitted to the action of heat in a distilling furnace, by which the mercury is sublimated.
6. The value of the silver annually taken from the mines in all parts of the world, is supposed to be about $20,000,000, of which Mexico and South America yield the greater part. The several silver mines of Europe and Asia produce about two millions and a half.
1. The artisan who forms certain articles of gold and silver, is called indifferently a goldsmith or a silversmith. The former denomination is most commonly employed in England, and the latter, in the United States.
2. The most common subjects of manufacture by the silversmith are cups, goblets, chalices, tankards, spoons, knives, forks, waiters, bread-trays, tea-pots, coffee-pots, cream-pots, sugar-bowls, sugar-tongs, and pencil-cases. Many of these articles he sometimes makes of gold; this is especially the case in Europe, and some parts of Asia. In the United States, the people are commonly satisfied with the less expensive metal.
3. A great proportion of the silver used by this mechanic, has been previously coined into dollars. In working these into different utensils or vessels, he first melts them in a crucible, and casts the silver into solid masses by pouring it into iron moulds; and having forged it on an anvil, he reduces it still further, and to a uniform thickness, by passing it several times between steel rollers. In giving additional explanations of the operations of the silversmith, we will describe the manner in which a plain tea-pot is manufactured.
4. In forming the body, or containing part, the plate, forged and rolled as just described, is cut into a circular form, and placed on a block of soft wood with a concave face, where it is beaten with a convex hammer, until it has been brought to a form much like that of a saucer. It is then placed upon an anvil, and beaten a while with a long-necked hammer with a round flattish face.
5. It is nextraisedto the proposed form by forging it on a long slender anvil, called astake, with a narrow-facedhammer, which spreads the metal perpendicularly from the bottom, or laterally, according to the position in which it may be held when brought in contact with the metal.
6. After the piece has been thus brought to the proposed form, it isplanishedall over by beating it with a small hammer on the outside, while it rests on a small steel head on the inside. During the performance of these operations, the silver is occasionallyannealedby heating it in the fire; but it is worked while in a cold state, except in the first forging, when it is wrought while a little below red heat.
7. The several pieces which compose a tea-pot of ordinary construction, amount to about fifteen, nearly all of which are rolled and forged in the manner just described. The knob on the lid, the handle, and the spout, are sometimes cast, and at other times, the two pieces of which they are formed are cut from a plate, and brought to a proper figure by impressing them with steel dies.
8. The figures seen on the cheaper kinds of silver tea-pots, as well as on other vessels and utensils, are commonly made by passing the plates or strips between engraved steel rollers, or by stamping them with steel dies. The dies are commonly brought in sudden and violent contact with the metal by means of an irondrop, which is let fall from a height upon it.
9. After the several parts have been brought to the proper shape, and to the requisite finish, they are firmly united together by means of a solder composed of about three parts of silver and one of brass and copper. Before the spout and handle are soldered on, the other parts, which have been thus united into one piece, are brought to a certain degree of polish.
10. This is effected chiefly in a lathe, by holding against the piece, while in rapid motion, first a file, then a scraper, and afterwards pumice stone andScotch stone. It is then held against a rapidly revolving brush, charged with fine brickdust and sweet oil. The handle and spout are next soldered on. After this, the vessel is annealed, and put inpickle, or, in other words, into a weak solution of oil of vitriol. It is then scoured with sand and water, and the whole operation is completed by burnishing the smooth parts with a steel instrument.
11. In the more expensive kinds of wares, the raised figures and the frosty appearance are produced by a process calledchasing. In executing this kind of work, a drawing is first made on the silver with a lead pencil. The several parts are then raised from the other side, corresponding as nearly as possible to it. The vessel or piece is then filled with, or placed upon, melted cement, composed of pitch and brick-dust; and, after the cement has become hard by cooling, the chaser reduces the raised parts to the form indicated by the drawing, by means of small steel punches. The roughness of surface, and frosty appearance, are produced by punches indented on the end.
12. The operations of the silversmith are exceedingly various, many of which could be hardly understood from mere description. We would, therefore, recommend to the curious, actual inspection, assuring them that the ingenuity displayed in executing the work in the different branches of the business, is well worthy of their attention. We will merely add, that spoons, knives, and forks, are not cast, as is frequently supposed, but forged from strips of silver cut from rolled sheets.
13. The earliest historical notice of gold and silver is found in the thirteenth chapter of Genesis, where it is stated that Abraham returned to Canaan from Egypt, "rich in cattle, in silver, and in gold." This event took place about 1920 years before Christ, it being but little more than 400 years after the deluge. Fromthe authority of the same book, we also learn, that during the life of this patriarch, those metals were employed as a medium of commercial intercourse, and as the materials for personal ornaments, vessels, and utensils.
14. From the preceding facts, we have reason to believe that gold and silver were known to the antediluvians; for, had not this been the case, they could hardly have been held in such estimation so early as the time of Abraham. In short, they were probably wrought even in the days of the original progenitor of the human race, as was evidently the case with iron and copper.
1. The great divisions of time, noted by uncivilized men, are those which are indicated by the changes of the moon, and the annual and diurnal revolutions of the earth; but the ingenuity of man was very early exercised in devising methods of measuring more minute periods of duration.
2. The earliest contrivance for effecting this object was the sun-dial. This instrument was known to the ancient Egyptians, Chaldeans, Chinese, and Bramins. It was likewise known to the Hebrews, at least as early as 740 years before Christ, in the days of Ahaz the king. The Greeks and the Romans borrowed it from their Eastern neighbors. The first sun-dial at Rome was set up by Papirius Cursor, about 300 years before Christ. Before this period, the Romans determined the time of day by the rude method of observing the length of shadows.
3. The sun-dial, as it is now constructed, consists of a plate, divided into twelve equal parts, like the face of a clock, on which the falling of a shadow indicates the time of day. The shadow is projected by the sun, through the intervention of a rod or the edgeof aplate stileerected on the plane of the dial. But, since the dial was useful only in the clear day, another instrument was invented, which could be used at all times, in every variety of situation; and to this was given the name ofclepsydra.
4. This instrument is supposed to have been invented in Egypt; but, at what period, or by whom, it is not stated. Its construction was varied, in different ages and countries, according with the particular modes of reckoning time; but the constant dropping or running of water from one vessel into another, through a small aperture, is the basis in all the forms which it has assumed. The time was indicated by the regularly increasing height of the water in the receiving vessel.
5. The clepsydra was introduced into Greece by Plato, near 400 years before Christ, and, about 200 years after this, into Rome, by Scipio Africanus. It is said that Pompey brought a valuable one from the East, and that Julius Cæsar met with one in England, by which he discovered that the summer nights were shorter there than in Italy.
6. The use which Pompey made of his instrument, was to limit the length of speeches in the senate. Hence he is said, by a historian of those times, to have been the first Roman who put bridles upon eloquence. A similar use was made of the clepsydra in the courts of justice, first in Greece, and afterwards in Rome.
7. A kind of water-clock, or clepsydra, adapted to the modern divisions of time, was invented near the middle of the seventeenth century; and these were extensively used, in various parts of Europe, for a considerable time; but they are now entirely superseded by our common clocks and watches, which are far more perfect in their operation, and, in all respects,better adapted to the purposes to which they are applied.
8. The invention of the clock is concealed in the greatest obscurity. Some writers attribute it to the monks, as this instrument was used in the twelfth century in the monasteries, to regulate the inmates in their attendance on prayers both by night and by day. Others suppose that a knowledge of this valuable instrument was derived from the Saracens, through the intercourse arising from the crusades. Be this as it may, clocks were but little known in Europe, until the beginning of the fourteenth century.
9. Richard, abbot of St. Alban's, England, made a clock in 1326, such as had never been heard of until then. It not only indicated the course of the sun and moon, but also the ebbing and flowing of the tide. Large clocks on steeples began to be used in this century. The first of this kind is supposed to have been made and put up in Padua by Jacobus Dondi.
10. A steeple clock was set up in Boulogne, in 1356; and, in 1364, Henry de Wyck, a German artist, placed one in the palace of Charles V., king of France. In 1368, three Dutchmen introduced clock-work into England, under the patronage of Edward III. Clocks began to be common both in England and on the Continent, about the end of the fifteenth century.
11. The clock of Henry de Wyck is the most ancient instrument of this kind of which we have a description. The wheels were made of wrought iron, and the teeth were cut by hand. In other respects, also, it was a rude piece of mechanism, and not at all capable of keeping time with accuracy. But, rude as it was, it is not likely that it was the invention of a single individual; but that, after the first rude machine was put in motion, it received several improvements from various persons. This has, at least, beenthe case with all the improvements made on the clock of Henry de Wyck, to the present day.
12. The application of the pendulum to clock-work appears to have been first made by Vincenzo Galileo, in 1649; but the improvement was rendered completely successful, in 1656, by Christian Huygens, a Dutch philosopher. The laws of the oscillation of the pendulum were first investigated by Galileo, the great Italian philosopher, and father of the Galileo just mentioned. His attention was attracted to this subject by the swinging of a lamp suspended from the ceiling of the Cathedral, at Pisa, his native city.
13. The clocks first made were of a large size, and were placed only in public edifices. The works were, at length, reduced in their dimensions, and these useful machines were gradually introduced into private dwellings. They were finally made of a portable size, and were carried about the person. These portable clocks had, for their maintaining power, a main-spring of steel, instead of a weight, which was used in the larger time-keepers.
14. The original pocket-watches differed but little, if at all, in the general plan of their construction, from the portable clocks just mentioned. The transition from one kind of instrument to the other was, therefore, obvious and easy; but the time of the change cannot be certainly determined. It is commonly admitted, however, that Peter Hele constructed the first watch, in 1510.
15. Watches appear to have been extensively manufactured at Nuremburg, in Germany, soon after their invention, as one of the names by which they were designated, wasNuremburg eggs. These instruments, as well as clocks, were in common use in France, in 1544, when the company of clock and watch makers of Paris was first incorporated.
16. In 1658, the spring balance was invented byDoctor Nathaniel Hooke, an English philosopher. At least the invention is attributed to him by his countrymen. On the Continent it is claimed for Christian Huygens. Before this improvement was made, the performance of watches was so defective, that the best of them could not be relied upon for accurate time an hour together. Their owners were obliged to set them often to the proper time, and wind them up twice a day.
17. After the great improvements had been effected in the clock and watch by Huygens and Hooke, several others of minor importance were successively made by different persons; but our limits do not allow us to give them a particular notice; we will only state that the repeating apparatus of both clocks and watches was invented, about the year 1676, by one Barlow, an Englishman; that the compensation or gridiron pendulum was invented by George Graham, of London, in 1715; and that jewels were applied to watches, to prevent friction, by one Facio, a German.
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. Greaterand 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 class of tradesmen, thefinisherorwatch-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, orinside 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. Brass 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.
COPPERSMITH.
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 quantities. The copper of commerce is principally 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 arsenic, a greater degree of heat is necessary. In such a case, it is spread upon a largefloor of a reverberatory furnace, and exposed to a greater heat. By this treatment, the sulphur and arsenic 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 thescoriainto 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 quantities 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, formspot-metal.Brassis 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 areprince's metal,pinchbeck,tombac, andbath-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 principal 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; andspeculum-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 substitute for iron and steel. The Corinthian brass, 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 brass and iron." This individual was the seventh generation from Adam, and was born about the year of the world 500.
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 constitutes 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 coveringof 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 brass and zinc, or zinc and lead, as in the case of those of smaller dimensions.
5. Brass 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 brass, are forged to the required form, and others are made of rolled sheets; but, in most cases, they pass through the hands of the brass-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 brass form a class of mechanics distinct from those who work in copper.
1. Trifling as the manufacture of buttons 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, glass, mother-of-pearl, bone, horn, and tortoise-shell, besides those which consist of moulds of wood or bone, covered with silk, mohair, or similar materials.
2. In making gilt buttons, theblanks, or bodies, are cut from rolled plates of brass, 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 buttons; 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 button, and held there temporarily with a wire clasp. A small quantity of solder and rosin having been applied to each shank, the buttons are exposed to heat on an iron plate, until the solder shall have melted. The shanks having been thus firmly soldered on, the buttons are turned off smoothly on their edges in a lathe.
4. The buttons 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 quantity 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 buttons, 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 butter, and in a fit state for use. Before the buttons areput into the amalgam, a small quantity of nitric acid is added.
6. The buttons having been covered with the amalgam, as before stated, the mercury is discharged, that the gold may adhere directly to the brass. This object is effected by heating the buttons 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 buttons are made of brass 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 buttons. The buttons are next polished in a lathe, with grindstone dust and oil, rotten stone and crocus martis. They are then boiled with a quantity of grained tin, in a solution of crude red tartar or argol, and lastly, finished with finely-pulverized crocus, applied with buff leather.
8. Glass buttons are made of various colors, in imitation of the opal and other precious stones. While manufacturing them, the glass is kept in a state of fusion, and a portion of it for each button 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.
1. There is scarcely any commodity cheaper than pins, and none which passes through the hands of a greater number of workmen in the manufacture, twenty-five persons being successively employed upon thematerial, 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 aspinning-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 thelengthsby 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 brass. 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, assume a white appearance. They are next polished by agitating them with a quantity 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 pricking. 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 brass wire was not known in England. Until that period, they were made of bone, ivory, or box-wood. Brass pins are first mentioned in the English statute book, in 1483, when those of foreign manufacture were prohibited.
10. Although these useful implements are made in London, and in several other places in England, yet Gloucester is the principal seat of this manufacture in that kingdom. It was introduced into that place, in 1626, by John Silsby, and it now contains nine distinct manufactories, in which are employed about 1500 persons, chiefly women and children. Pins are also manufactured extensively in the villages near Paris, and in several other places in France, as well as in Germany.
11. The business of making pins has been lately commenced in the city of New-York, and it is said that the experiment has been so successful, both in the perfection of the workmanship, and in the rapidity of the production, that pins of American manufacture bid fair to compete, at least, with those of foreign countries.
TINPLATE WORKER.
1. Tin is a whitish metal, less elastic, and less sonorous than any other metal, except lead. It is found in the mountains which separate Gallicia from Portugal, and in the mountains between Saxony and Bohemia. It also occurs in the peninsula of Molucca, in India, Mexico, and Chili. But the mines of Cornwall and Devonshire, in England, are more productive than those of all other countries united.
2. There are two ores of tin, one of which is calledtin stone, and the othertin pyrites; the former of these is the kind from which the metal is extracted. The ore is usually found in veins, which often penetrate the hardest rocks. When near the surface of the earth, or at their commencement, they are very small,but they increase in size, as they penetrate the earth. The direction of these veins, or, as the miners call them,lodes, is usually east and west.
3. The miners follow the lode, wheresoever it may lead; and, when they extend to such a depth, that the waters become troublesome in the mine, as is frequently the case, they are pumped up with machinery worked by steam, or drawn off by means of a drain, called anadit. The latter method is generally adopted, when practicable.
4. The ore is raised to the surface through shafts, which have been sunk in a perpendicular direction upon the vein. At the top of the shaft, is placed a windlass, to draw up thekibbuts, or baskets, containing the ore. Near St. Austle, in Cornwall, is a mine which has not less than fifty shafts, half of which are now in use. Some of the veins have been worked a full mile, and some of the shafts are nearly seven hundred feet deep.
5. At St. Austle Moor, there is a mine ofstream tin, about three miles in length. The tin, together with other substances, has been deposited in a valley, by means of small streams from the hills. The deposite is about twenty feet deep, and the several materials of which it is composed, have settled in strata, according to their specific gravity. The ore, being the heaviest, is, of course, found at the bottom.
6. The ore, from whatever source it may be obtained, is first pulverized in a stamping mill, and then washed, to free it from the stony matter with which it may be united. The ore, thus partially freed from foreign matter, is put into a reverberatory furnace, with fuel and limestone, and heated intensely. The contents of the furnace having been brought to a state of fusion, the lime unites with the earthy matters, and flows with them into a liquid glass, while the carbon of the coal unites with the tin. The metal sinks, byits specific gravity, to the bottom of the furnace, and is let out, after having been exposed to the heat about ten hours.
7. The tin thus obtained, is very impure; it therefore requires a second fusion, to render it fit for use. After having been melted a second time, it is cast into blocks weighing about three hundred pounds. These blocks are taken to places designated by law, and there stamped, by inspectors appointed for the purpose by the Duke of Cornwall. In performing this operation, the inspector cuts off a corner, and stamps the block at that place, with the proper seal, and with the name of the smelter. These precautions give assurance, that the metal is pure, and that the duty has been paid.
8. The duty is four shillings sterling per hundred weight, which is paid to the Duke of Cornwall, who is also Prince of Wales. The revenue from this source amounts to about thirty thousand pounds a year. The owner of the soil also receives one sixth, or one eighth of the ore as hisdish, as the miners call it. The miners and the smelters receive certain proportions of the metal for their services.
9. Tin was procured from Britain at a very early period. The Phœnicians are said by Strabo to have passed the Pillars of Hercules, now the Straits of Gibraltar, about 1200 years before Christ. But the time at which they discovered the tin islands, which they denominatedCassorides, cannot be ascertained from history, although it is evident from many circumstances, that the Scilly Islands, and the western ports of Britain, were the places from which these early navigators procured the tin with which they supplied the parts of the world to which they traded.
10. For a long time, the Phœnicians and the Carthaginians enjoyed the tin trade, to the exclusion of all other nations. After the destruction of Carthage bythe Romans, a colony of Phocean Greeks, established at Marseilles, carried on this trade; but it came into the hands of the Romans, after the conquest of Britain by Julius Cæsar.
11. The Cornish mines furnish incontestable proofs of having been worked many hundred years ago. In digging to the depth of forty or fifty fathoms, the miners frequently meet with large timbers imbedded in the ore. Tools for mining have also been found in the same, or similar situations. The mines, therefore, which had been exhausted of the ore, have, in the course of time, been replenished by a process of nature.
12. To what purposes the ancients applied all the tin which they procured at so much labor and cost, is not precisely known. It is probable, that the Tyrians consumed a portion of it, in dyeing their purple and scarlet. It formed then, as it now does, many important alloys with copper. The mirrors of antiquity were made of a composition of these metals.
13. The method of extracting tin from its ores was probably very defective in ancient times. At least, it was so for several centuries before the time of Elizabeth, when Sir Francis Godolphin introduced great improvements in the tin works. The use of the reverberatory furnace was commenced, about the beginning of the eighteenth century, and soon after pit-coal was substituted for charcoal.
14. This metal, in its solid state, is calledblock-tin. It is applied, without any admixture with any other metal, to the formation of vessels, which are not to be exposed to a temperature much above that of hot water. A kind of ware, calledbiddery ware, is made of tin alloyed with a little copper. The vessels made of this composition, are rendered black by the application of nitre, common salt, and sal ammoniac.Foilis also made by pressing it between steel rollers,or by hammering it, as in the case of gold by the gold-beaters.
15. But tin is most extensively applied as a coating to other metals, stronger than itself, and more subject to oxydation. The places which are usually denominated tin, are thin sheets of iron coated with this metal. The iron is reduced to thin plates in a rolling-mill, and these are prepared for being tinned, by first steeping them in water acidulated with muriatic acid, and then freeing them from oxyde by heating, scaling, and rolling them.
16. The tin is melted in deep oblong vessels, and kept in a state of fusion by a charcoal fire. To preserve its surface from oxydation, a quantity of fat or oil is kept floating upon it. The plates are dipped perpendicularly into the tin, and held there for some time. When withdrawn, they are found to have acquired a bright coating of the melted metal. The dipping is performed three times forsingle tin plate, and six times fordouble tin plate. The tin penetrates the iron, and forms an alloy.
17. Various articles of iron, such as spoons, nails, bridle-bits, and small chains, are coated with tin, by immersing them in that metal, while in a state of fusion. The great affinity of tin and copper, renders it practicable to apply a thin layer of the former metal to the surface of the latter; and this is often done, as stated in the article on the coppersmith.
18. Tin and quicksilver are applied to the polished surface of glass, for the purpose of forming mirrors. In silvering plain looking-glasses, a flat, horizontal slab is used as a table. This is first covered with paper, and then with a sheet of tin foil of the size of the glass. A quantity of quicksilver is next laid on the foil, and spread over it with a roll of cloth, or with a hare's foot.
19. After as much quicksilver as the surface willhold, has been spread on, and while it is yet in a fluid state, the glass is shoved on the sheet of foil from the edge of the table, driving a part of the liquid metal before it. The glass is then placed in an inclined position, that every unnecessary portion of the quicksilver may be drained off, after which it is again laid flat upon the slab, and pressed for a considerable time with heavy weights. The remaining quicksilver amalgamates with the tin, and forms a permanent, reflecting surface.
1. The materials on which the tinner, or tin-plate worker, operates, are the rolled sheets of iron, coated with tin, as just described. He procures the sheets by the box, and applies them to the roofs and other parts of houses, or works them up into various utensils, such as pails, pans, bake-ovens, measures, cups, and ducts for conveying water from the roofs of houses.
2. In making the different articles, the sheets are cut into pieces of proper size, with a huge pair of shears, and these are brought to the proposed form by different tools, adapted to the purpose. The several parts are united by means of a solder made of a composition of tin and lead. The solder is melted, and made to run to any part, at the will of the workman, by means of a copper instrument, heated for the purpose in a small furnace with a charcoal fire.
3. On examining almost any vessel of tin ware, it will be perceived, that, where the parts are united, one of the edges, at least, and sometimes both, are turned, that the solder may be easily and advantageously applied. It will also be discovered that iron wire is applied to those parts requiring more strength than is possessed by the tin itself. The edges and handles are especially strengthened in this manner.
4. The edges of the tin were formerly turned on asteel edge, or a kind of anvil called astock, with a mallet; and, in some cases, this method is still pursued; but this part of the work is now more expeditiously performed, by means of several machines invented by Seth Peck, of Hartford Co., Connecticut. These machines greatly expedite the manufacture of tin wares, and have contributed much towards reducing their price.
5. This manufacture is an extensive branch of our domestic industry; and vast quantities of tin, in the shape of various utensils, are sold in different parts of the United States, by a class of itinerant merchants, calledtin-pedlers, who receive in payment for their goods, rags, old pewter, brass, and copper, together with feathers, hogs' bristles, and sometimes ready money.
1. Next to iron, lead is the most extensively diffused, and the most abundant metal. It is found in various combinations in nature; but that mineralized by sulphur is the most abundant. This ore is denominatedgalenaby the mineralogists, and is the kind from which nearly all the lead of commerce is extracted.
2. The ore having been powdered, and freed, as far as possible, from stony matter, is fused either in a blast or reverberatory furnace. In the smelting, lime is used as a flux, and this combines with the sulphur and earthy matters, while the lead unites with the carbon of the fuel, and sinks to the bottom of the furnace, whence it is occasionally let out into a reservoir.
3. Lead extracted from galena, often contains a sufficient proportion of silver to render it an object to extract it. This is done by oxydizing the lead by means of heat, and a current of air. At the end of this operation, the silver remains with a small quantityof lead, which is afterwards separated by the process of cupellation. The oxyde is applied to the purposes for which it is used, or it is reduced again to a metallic state.
4. The lead mines on the Mississippi are very productive, and very extensive. The principal mines are in the neighborhood of Galena, in the north-western part of Illinois, and these are the richest on the globe. The lead mines in the vicinity of Potosi, Missouri, are also very productive. About 3,000,000 pounds are annually smelted in the United States.
5. Lead, on account of its easy fusibility and softness, can be readily applied to a variety of purposes. It is cast in moulds, to form weights, bullets, and other small articles. Cisterns are lined, and roofs, &c., are covered with sheet lead; and also in the construction of pumps and aqueducts, leaden pipes are considerably used. The mechanic who applies this metal to these purposes, is called a plumber.
6. Lead is cast into sheets in sand, on large tables having a high ledge on each side. The melted lead is poured out upon the surface from a box, which is made to move on rollers across the table, and is equalized, by passing over it a straight piece of wood called astrike. The sheets thus formed, are afterwards reduced in thickness, and spread to greater dimensions, by compressing them between steel rollers.
7. Leaden pipes may be made in various ways. They were at first formed of sheet lead, bent round a cylindrical bar, or mandrel, and then soldered; but pipes formed in this manner, were liable to crack and break. The second method consists in casting successive portions of the tube in a cylindrical mould, having in it a core. As soon as the tube gets cold, it is drawn nearly out of the mould, and more lead is poured in, which unites with the tube previously formed.But pipes cast in this way are found to have imperfections, arising from flaws and air bubbles.
8. In the third method, which is the one most commonly practised, a thick tube of lead is cast upon one end of a long polished iron cylinder, or mandrel, of the size of the bore of the intended pipe. The lead is then reduced, and drawn out in length, either by drawing it on the mandrel through circular holes of different sizes, in a steel plate, or by rolling it between contiguous rollers, which have a semicircular groove cut round the circumference of each.
9. The fourth method consists in forcing melted lead, by means of a pump, into one end of a mould, while it is discharged in the form of a pipe, at the opposite end. Care is taken so to regulate the temperature, that the lead is chilled just before it leaves the mould.
10.Shotis likewise made of lead. These instruments of death are usually cast in high towers constructed for the purpose. The lead is previously alloyed with a small portion of arsenic, to increase the cohesion of its particles, and to cause it to assume more readily the globular form. It is melted at the top of the tower, and poured into a vessel perforated at the bottom with a great number of holes.
11. The lead, after running through these perforations, immediately separates into drops, which cool in falling through the height of the tower. They are received below in a reservoir of water, which breaks the fall. The shot are then proved by rolling them down a board placed in an inclined position. Those which are irregular in shape roll off at the sides, or stop, while the spherical ones continue on to the end.