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Needles
"T AKE from a case one of the finest needles, examine its sharp point, its tiny, almost imperceptible eye, and note finally the polish, the shine. Tell me if this pretty little tool, so perfect in its minuteness, would not seem to require for its manufacture the superhuman fingers of a fairy rather than man's heavy hands. Nevertheless it is robust workmen with knotty fingers blackened by the forge and covered with great calluses that do this most delicate work. And how many workers does it take to make one needle?—one only? For the manufacture of a pin, I have already told you, it takes fourteen different workmen; for the manufacture of a needle it requires the coöperation of one hundred and twenty, each of whom has his special work. And yet the average price of a needle is about one centime. "The metal of needles is steel, which is obtained by adding carbon to iron heated to a very high temperature. Under this treatment iron changes its nature a little, incorporating a very small quantity of carbon and thus becoming exceedingly hard, but at the same time brittle. A needle must be very hard in order not to bend under the pressure of the thimble forcing it through the thickness of the material on which the seamstress is at work, and also in order that the point may not become blunted, but always retain the same power of penetration. Steel, the hardest of all the metals, is the only one that fulfils these conditions of resistance; neither copper nor iron nor the precious metals, gold and silver, could replace it. A gold needle, for example, in spite of its intrinsic value, would be useless, becoming blunted and twisted before using up its first needleful of thread. Steel alone is suited to the manufacture of needles, though unfortunately this metal is brittle, and the more so the harder it is." "But I should think," Marie interposed, "that since steel is so hard it ought not to break."
"You will think otherwise if you listen to me a while. Hardness is the degree of resistance that a body opposes to being cut, scratched, worn away by another. Of two bodies rubbing against each other the harder is that which cuts the other, the softer is that which is cut. Steel, which scratches iron, is harder than iron; in its turn glass is harder than steel, because it can cut the steel without being cut by it. But a diamond is still harder than glass, since it scratches glass and glass cannot scratch it. In fact a diamond is the hardest of all known substances: it scratches all bodies and is scratched by none. Glaziers take advantage of this extreme hardness: they cut their panes of glass with the point of a diamond." "I have heard," said Claire, "that a diamond placed on an anvil and struck with a hammer stands the blows without breaking and penetrates into the iron of the anvil, it is so hard." "That is a great mistake," replied Uncle Paul. "A diamond breaks like glass, and he would be very ill-advised who should submit the precious stone to the proof of a hammer. At the first blow there would be nothing left but a little worthless dust. You see by these different examples that hardness and brittleness are often united. Steel is very hard, glass still harder, and diamond the hardest of all substances; nevertheless all three are brittle. That explains to you why needles of excellent steel, which gives them their rigidity and power of penetration, nevertheless break like glass in clumsy fingers. "Now I come to the subject of manufacture, from which the properties of steel turned us for a moment. The metal is drawn out into wire by means of a draw-plate; then this wire, several strands at a time, is cut into pieces twice the length of a needle, just as in pin-making. The pieces are pointed at each end, first on a revolving sandstone similar to an ordinary grindstone, then on a wooden wheel covered with a thin layer of oil and a very fine, hard powder called emery. Imagine glass reduced to an impalpable powder and you will have a sufficiently correct idea of what emery is. The first process gives us a more or less coarse point; the second sharpens this point with extreme nicety. "The pieces thus pointed at both ends are cut into two equal parts, each one of which is to be a needle. The workman then takes in his fingers four or five of these unfinished needles, spreads them out like a fan and puts the large end of them on a little anvil; then with a light blow of the hammer he slightly flattens the head of each. It is in this flattened end that later on the eyelet or hole of the needle will be pierced." "But you just told us, Uncle," Marie interrupted, "that good steel is brittle, the same as glass; yet the workman flattens the head of his needles with a hammer without breaking anything." "Your remark is very timely, for before going further we have to take note of one of the most curious properties of steel. I must tell you that it is only by tempering that this metal becomes hard and at the same time brittle. Tempering steel is heating it red-hot and then cooling it quickly by plunging it into cold water. Until it undergoes this operation steel is no harder than iron; but, to compensate for this softness, it can be hammered, forged, and in fact worked in all sorts of ways without risk of breaking. Once tempered, it is very hard and at the same time so brittle that it can never henceforth stand the blow of a hammer. Accordingly needles are not tempered until near the end of the process of manufacture; before that they are neither hard nor brittle and can be worked as easily as iron itself. "If you look at a needle attentively you will see that the head is not only flattened but also hollowed out a little on each side in the form of a gutter or groove which serves to hold the thread. To obtain this double groove, the workman places the needles, one by one, between two tiny steel teeth which, moved by machinery, open and shut like two almost invisible jaws. Bitten hard by the shutting of these two teeth, the head of the needle is indented with a groove on each side. "Now the eye must be pierced, an operation of unequalled delicacy. Two workmen cooperate in this, each equipped with a steel awl whose fineness corresponds with the hole to be made. The first places the head of the needle on a leaden block, puts the point of his instrument in the groove on one side, and, striking a blow with the hammer on the head of the awl, thus obtains not a complete hole but merely a dimple. The needle is then turned over and receives a similar dimple on the other side. The other workman takes the needles and with the aid of his awl removes the tiny bit of steel that separates the two dimples. Behold the eye completely finished. "Probably no work requires such sureness of hand and precision of sight as the piercing of the eye of a needle. Certainly he has no trembling fingers or dimmed eyesight who can, without faltering, apply his steel point to the fine head of a needle, strike with perfect accuracy the blow of the hammer, and open the imperceptible orifice that my eyes can scarcely find when I want to thread a needle." "There are needles so small," remarked Marie, "that I really don't see how anyone can manage to make an eye in them." "This incomprehensible achievement is mostly the work of astonishingly skilful children. So skilful, indeed, are some of them that they can make a hole in a hair and pass a second hair through this hole." "Then the needle's eye," said Emile, "which seems such a difficult piece of work to us, is only child's play to them." "Child's play indeed, so quick and dexterous are they at it. And they have still another kind of dexterity that would astonish you no less. To make the needles easier to handle in the process of manufacture, they must be placed so that they all point the same way; but as in passing from one operation to another, from one workman to another, they become more or less disarranged, it is necessary to arrange them in order again, all the points at one end, all the heads at the other. For us there would be no way but to pick them up one by one; with these children this delicate task is but the work of an instant. They take a handful of needles all in disorder, shake them in the hollow of the hand, and that is enough; order is reestablished, the heads are together, the points together. "The eye completed, the next process is tempering, to give the steel its required hardness. The needles are arranged on a plate of sheet-iron, which is then placed on red-hot coals. When sufficiently heated, the needles are dropped quickly into a bucket of cold water. This produces in them the hardness characteristic of steel, and its accompanying brittleness. "As a finishing touch the needles must be polished till they shine brightly. In parcels of fifteen or twenty thousand each they are sprinkled with oil and emery and wrapped up in coarse canvas tied at both ends. These round packages, these rolls, are placed side by side on a large table and covered with a weighted tray. Workmen or machinery then make the tray pass back and forth over the table unceasingly for a couple of days. By this process the packages, drawn this way and that by the tray, roll along the table, and the needles, rubbing against one another, are polished by the emery with which they are sprinkled. "On coming out of the polishing machine the needles, soiled with refuse of oil and detached particles of steel, are cleaned by washing with hot water and soap. It remains now only to dry them well, discard those that the rude operation of polishing has broken, and finally wrap with paper, in packages of a hundred, those that have no defect. The most celebrated needles come from England, but needles are also made in France, at Aigle in the department of Orne." |
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