Makers of Many Things Part 3

If any one should give you a lump of clay and ask you to make a bowl, how should you set about it? The first thing would be, of course, to put it on a table so you could work on it with both hands. You would make a depression at the top and push out the sides and smooth them as best you could. It would result in a rough, uneven sort of bowl, and before it was done, you would have made one discovery, namely, that if the table only turned around in front of you, you could see all sides of the bowl from the same position, and it would be easier to make it regular. This is just what the potter's wheel does. It is really two horizontal wheels. The upper one is a disk a foot or two in diameter.

This is connected by a shaft with the lower one, which is much larger.

When the potter was at work at a wheel of this sort, he stood on one foot and turned the lower wheel with the other, thus setting the upper wheel in motion. This was called a "kick-wheel." As wheels are made now, the potter sits at his work and turns the wheel by means of a treadle.

Almost any kind of clay will make a dish, but no one kind will make it so well that the addition of some other kind would not improve it.

Whatever clays are chosen, they must be prepared with great care to make sure that not one grain in them is coa.r.s.er than any other.

Sometimes one will slip through, and you can see on the finished dish what a bad-looking place it makes. Even for the coa.r.s.est earthenware, such as flower-pots, the moist clay is forced down a cylinder and through a wire sieve; and for stoneware and porcelain it has to go through several processes. When flint and feldspar are used, they are ground fine at the quarry. On reaching the factory, they are mixed with the proper quant.i.ties of other clays--but in just what proportions is one of the secrets of the trade. Then they go into "plungers" or "blungers," great round tanks with arms extending from a shaft in the center. The shaft revolves and the arms beat the clay till all the sand and pebbles have settled on the bottom, and the fine clay grains are floating in the water above them. These pa.s.s into canvas bags. The water is forced out through the canvas, and on every bag there is left a thin sheet of moist clay. If this is to be used for the finest work, it is ground and pounded and washed still more, until it is a wonder that any of it survives; then it is sifted through a screen so fine that its meshes are only one one hundred and fiftieth of an inch across. Now it becomes "slip," and after a little more beating and tumbling about, it is ready to go to the man at the wheel.

This man is called the "thrower," because he lifts the lump of clay above his head and throws it down heavily upon the center of the wheel. The things that happen to that lump of clay when he touches it and the wheel revolves seem like the work of magic. He presses his thumbs into it from above and draws the walls up between his thumbs and fingers. He clasps his hands around it, and it grows tall and slender. He lays his finger on the top of the little column of clay, and it flattens in a moment. He points his finger at it, barely touching it, and a little groove appears, running around the whole ma.s.s. He seems to be wasting considerable time in playing with it, but all the while he is making sure that the clay is perfectly uniform and that there are no bubbles of air in it. He holds a piece of leather against the outside surface and a wet sponge against the inside, to make them perfectly smooth; and in a moment he has made a bowl. He holds his bent finger against the top of the bowl, and it becomes a vase. With another touch of his magical finger the top of the vase rolls over into a lip. If he makes a cup or a mug, he models a handle in clay and fastens it in place with slip. When it is done, he draws a wire deftly between the article and the table, and puts it on a board to dry.

When you watch a potter at work, it all looks so simple and easy that you feel sure you could do it; but see how skillfully he uses his hands, how strong they are, and yet how lithe and delicate in their movements. See into what odd positions he sometimes stretches them; and yet these are plainly the only positions in which they could do their work. See how every finger does just what he wishes it to do.

Notice all these things, and you will not be so certain that making pottery is the easiest thing in the world.

No two pieces of hand work are exactly the same; and skillful as the potter is, his pieces are not precisely alike. Many of them therefore are pa.s.sed over to the turner for finis.h.i.+ng. He uses an ordinary lathe, and with this he thins any place that may be a little too thick, rounds the edge, and smooths it. The article is partly dried when he takes it, and so its walls can be cut thinner. When it leaves his lathe, all signs of hand work have vanished, but the dish is exactly like the others of the set, and this is what the greater number of people want. In some potteries there is hardly a throwing wheel in use, and articles are formed in plaster of Paris moulds.

There are two ways of using these moulds. By one method, the mould is put upon a "jigger," a power machine which keeps it revolving, and clay is pressed against its walls from within. Above the mould is a piece of iron cut in the shape of the inside curve of the bowl or whatever is being made. This skims off all the extra clay from the inside of the walls. Plates and saucers are made on a jigger. The mould used for this work is a model of the top of the plate. The workman makes a sort of pancake of clay and throws it upon the mould.

A second mould, shaped like half of the bottom of the plate, is brought down close and revolves, cutting off all the extra clay and shaping the bottom of the plate.

When the very finest ware is to be made, the mould is used in quite another fas.h.i.+on. If a pitcher, for instance, is to be cast, the mould is made in two sections and tied tightly together. Then the slip is poured into it and left for a while. The plaster of Paris absorbs the water and a layer of clay is formed all about the walls. When this is thick enough, the liquid is poured out, and after the pitcher has dried awhile, the mould is carefully opened and the pitcher is very gently taken out. The handle is made in a little mould of its own and fastened on with slip. "Eggsh.e.l.l" porcelain is made in this way. The clay sh.e.l.l becomes smaller as it dries, so there is no trouble about removing it from the mould--if one knows how. If a large article is to be cast, the mould is made in sections. Of course this fine ware must all be made by hand, especially as machines do not work well with the finest clays; but cheap dishes are all made by machinery.

After any clay article is thrown, or moulded, or cast, it is pa.s.sed through a little doorway and set upon a shelf in a great revolving cage. The air in this cage is kept at about 85 F.; but this heat is nothing to what is to follow; and after the articles are thoroughly dry, they are placed in boxes of coa.r.s.e fire-clay, which are called "saggers," piled up in a kiln, the doors are closed, and the fires are lighted. For a day and night, sometimes for two days and two nights, the fires burn. The heat goes up to 2000 or 2500 F. Every few hours test pieces, which were put in for this purpose, are taken out. When they are found to be sufficiently baked, the fire-holes are bricked up and the furnace is left for two days longer to cool. The ware is then called "biscuit."

Biscuit is dull and porous. It is soon to be glazed, but first whatever underglaze decorating is desired may be done. Sometimes the decorations are painted by hand, and sometimes they are printed on thin paper, laid upon the ware, and rubbed softly till they stick fast. After a while the paper is pulled off, but the colors remain. Gold must be applied over the glaze, and the article fired a second time.

After this decorating, the ware is generally pa.s.sed to a man who stands before a tub of glaze, and dips in each article, though sometimes he stands before the pieces of ware and sprays them with an air brush. Many different kinds of glaze are used, made of ground flint, feldspar, white clay, and other substances. Common sea salt works exceedingly well, not in liquid form, but thrown directly into the fire. The chief thing to look out for in making a glaze is to see that the materials in it are so nearly like those in the ware that they will not contract unevenly and make little cracks. This glaze is dried in a hot room, then looked over by "trimmers," who sc.r.a.pe it off from such parts as the feet of cups and plates, so that they will not stick to the saggers in firing. Besides this, little props of burned clay are used to hold the dishes up and keep them from touching one another. These props have fanciful names, such as "spurs," "stilts,"

"c.o.c.kspurs," etc. Often you can see on the bottom of a plate the marks made by these supports.

[Ill.u.s.tration: IN THE POTTERY

Pieces of coa.r.s.e pottery being delivered to the kiln for firing.]

The articles now are sent to a kiln to be fired. When they come out there is another chance for decorating, for colors may be put on, and another firing will make them look like underglaze painting If the decorator wishes the ware to have the appearance of being ornamented with ma.s.ses of gold, he can trace his design in yellow paste, fire it, cover it with gold, and fire it again. To make the "gilt-band china"

so beloved by the good housewives of the last century, the decorator puts the plate upon a horizontal wheel, holds his brush full of gold against it, and turns the wheel slowly. Sometimes the outlines of a design are printed and the coloring put in by hand. When broad bands of color are desired to be put around a plate or other article, the decorator sometimes brushes on an adhesive oil where the color is to go, and paints the rest of the plate with some water-color and sugar; then when the oil is partly dry, he dusts on the color in the form of powder. A plunge into water will wash away the water-color and leave the oil with the powder sticking to it. Shaded groundwork is made with an atomizer. Indeed, there are almost as many methods of decorating wares of clay as there are persons who work at it. The results are what might be expected from the prices; some articles are so cheap and gaudy that any one will soon tire of them. Others are really artistic and will be a "joy forever"--until they break.

VIII

HOW THE WHEELS OF A WATCH GO AROUND

If an electric automobile could be charged in fifteen seconds and then would run for forty hours without recharging, it would be looked upon as a great wonder; but to wind a watch in fifteen seconds and have it run for forty hours is so common that we forget what a wonder it is.

When you wind your watch, you put some of the strength of your own right hand into it, and that is what makes it go. Every turn of the key or the stem winds up tighter and tighter a spring from one to two feet long, but so slender that it would take thousands to weigh a pound. This is the main spring. It is coiled up in a cup-shaped piece of metal called a "barrel"; and so your own energy is literally barreled up in your watch. The outer end of this spring is held fast by a hook on the inside of the barrel; the inner end is hooked to the hub of a wheel which is called the "main wheel," and around this hub the spring is coiled.

This spring has three things to do. It must send the "short hand,"

or hour hand, around the dial or face of the watch, once in twelve hours; it must send the "long hand," or minute hand, around once an hour; and it must also send the little "second hand" around its own tiny circle once a minute. To do this work requires four wheels. The first or main wheel is connected with the winding arrangements, and sets in motion the second, or center wheel, so called because it is usually in the center of the watch. This center wheel revolves once an hour and turns the minute hand. By a skillful arrangement of cogs it also moves the hour hand around the dial once in twelve hours. The center wheel moves the third wheel. The chief business of the third wheel is to make the fourth turn in the same direction as the center wheel. The fourth wheel revolves once a minute, and with it turns the tiny second hand.

Suppose that a watch has been made with only the main spring, the four wheels, and the three hands, what would happen when it was wound? You can tell very easily by winding up a mechanical mouse or a train of cars or any other toy that goes by a spring. It will go fast at first, then more and more slowly, then it will stop. This sort of motion might do for a mouse, but it would not answer for a watch. A watch must move with steadiness and regularity. To bring this about, there is a fifth wheel. Its fifteen teeth are shaped like hooks, and it has seven accompaniments, the balance wheel, the hair spring, and five others. This wheel, together with its accompaniments, is able to stop the motion of the watch five times a second and start it again so quickly that we do not realize its having been stopped at all. A tiny arm holds the wheel firmly, and then lets it escape. Therefore, the fifth wheel and its accompaniments are called the "escapement." This catching and letting go is what makes the ticking.

A watch made in this way would run very well until a hot day or a cold day came; then there would be trouble. Heat makes metals expand and makes springs less elastic. Therefore in a hot day the watch would go more slowly and so lose time; while in a cold day it would go too fast and would gain time. This fault is corrected by the balance, a wheel whose rim is not one circle, but two half-circles, and so cunningly made that the hotter this rim grows, the smaller its diameter becomes.

In the rim of the wheel are tiny holes into which screws may be screwed. By adding screws or taking some away, or changing the position of some of them, the movement of the watch can be made to go faster or slower.

All this would be difficult enough to manage if a watch was as large as a cart wheel, with wheels a foot in diameter; but it does seem a marvel how so many kinds of wheels and screws and springs, one hundred and fifty in all, can be put into a case sometimes not more than an inch in diameter, and can find room to work; and it is quite as much of a marvel how they can be manufactured and handled.

Remembering how accurate every piece must be, it is no wonder that in Switzerland, where all this work used to be done by hand, a boy had to go to a "watch school" for fourteen years before he was considered able to make a really fine watch. He began at the beginning and was taught to make, first, wooden handles for his tools, then the tools themselves, such as files, screw drivers, etc. His next work was to make wooden watchcases as large as dinner-plates. After this, he was given the frame to which the various wheels of a watch are fastened and was taught how and where to drill the holes for wheels and screws.

After lessons in making the finer tools to be used, he was allowed to make a watch frame. All this took several years, for he had to do the same work over and over until his teachers were satisfied with it.

Then he was promoted to the second room. Here he learned to adjust the stem-winding parts, to do fine cutting and filing, and to make watches that would strike the hour and even the minute. Room three was called the "train room," because the wheels of a watch are spoken of as "the train." The model watch in this room was as large as a saucer. The young man had to study every detail of this, and also to learn the use of a delicate little machine doing such fine work that it could cut twenty-four hundred tiny cogs on one of the little wheels of a watch.

In the fourth room he learned to make the escapement wheel and some other parts; and he had to make them, not merely pa.s.sably, but excellently. In the fifth and last room, he must do the careful, patient work that makes a watch go perfectly. There are special little curves that must be given to the hair spring; and the screws on the balance wheel must be carefully adjusted. If the watch ran faster when it was lying down than when it was hanging up, he learned that certain ones of the bearings were too coa.r.s.e and must be made finer. In short, he must be able to make a watch that, whether hanging up or lying down, and whether the weather was hot or cold, would not vary from correct time more than two and a half seconds a day at the most.

Then, and not till then, was the student regarded as a first-cla.s.s watchmaker.

The graduate of such a school knew how to make a whole watch, but he usually limited his work to some one part. Every part of a watch was made expressly for that watch, but sometimes a hundred different persons worked on it. The very best of the Swiss watches were exceedingly good; the poorest were very bad, and much worse to own than a poor American watch because it costs more to repair a Swiss watch than an American watch.

[Ill.u.s.tration: _Courtesy Waltham Watch Co._

WHERE WATCHES ARE MADE

Once a single man made a whole watch by hand. Now one watch may be the product of a hundred hands, each man doing his particular part.]

Even though in America the parts of watches are made by machinery, an apprentice has to undergo just as careful and just as extended training here as in Switzerland. A poor watch is worse than none at all, and careless work would not be tolerated in any watch factory.

Of late even Switzerland has been importing American machinery in order to compete with the United States. These machines do such careful, minute, intricate work that, as you stand and watch them, you feel as if they must know what they are about. One of them takes the frame,--that is, the plates to which the wheels are fastened,--makes it of the proper thinness, cuts the necessary holes in it, and pa.s.ses it over to the next machine, which is reaching out for it. The feeder gives the first machine another plate; and so the work goes on down a whole line of machines. At length the plate is taken in hand by a machine, or rather a group of machines, which can do almost anything.

Before they let it go, they actually perform one hundred and forty-two different operations, each bringing it nearer completion. These machines are automatic, but nevertheless they must be constantly watched by expert machinists to keep them in order and make sure of their turning out perfect work.

While one line of machines has been perfecting the plate, others have been at work on screws and wheels and springs. As many of these as are needed for one watch are put into a little division of a tray and carried to another room for its jewels and the rest of its outfit.

The jewels, which are pieces of rubies, sapphires, garnets, or even diamonds, are very valuable to a watch. When you know that the little wheels are in constant motion, and that the balance wheel, for instance, vibrates eighteen thousand times an hour, it is plain that a vast amount of wear comes upon the spot where the pivots of these wheels rest. No metal can be made smooth enough to prevent friction, and there is no metal hard enough to prevent wear. The "jewels" are smoother and harder. They are sawed into slabs so thin that fifty of them piled up would measure only an inch. These are stuck to blocks to be polished, cut into disks flat on one side but with a little depression on the other to receive oil, bored through the center, and placed wherever the wear is greatest--provided the purchaser is willing to pay for them. A "full-jeweled" watch contains twenty-three jewels; that is, in twenty-three of the places where the most severe wear comes, or where friction might prevent the watch from going with perfect smoothness, there will be practically no wear and no friction.

A low-priced watch contains only seven jewels, but if you want a watch to last, it pays to buy one that is full-jeweled.

And now these plates and wheels and screws are to be put together, or "a.s.sembled," as this work is called. This is a simple matter just as soon as one has learned where the different parts belong, for they are made by machinery and are sure to fit. After the a.s.sembling comes the adjusting of the balance wheel and the hair spring. There is nothing simple about this work, for the tiny screws with the large heads must be put into the rim of the balance wheel with the utmost care, or else all the other work will be useless, and the watch will not be a perfect time keeper; that is, one that neither loses nor gains more than thirty seconds a month.

It is said that the earliest watches made in Europe cost fifteen hundred dollars and took a year to make. There has always been a demand for a cheap pocket timepiece, and of late this demand has been satisfied by the manufacture of the "dollar watch." Properly speaking, this is not a watch at all, but a small spring clock. It has no jewels, and its parts are stamped out of sheets of bra.s.s or steel by machinery. The hair springs are made in coils of eight and then broken apart; and the main springs are made by the mile. Twenty holes are drilled at a time, and the factory in which "dollar watches" were first manufactured is now able to turn out fifteen thousand a day.

IX

THE MAKING OF SHOES

Did you ever stop to think how many different qualities you expect in a shoe? You want the sole to be hard and firm so as to protect your feet in rough walking; and also soft and yielding so as to feel springy and not board-like. You want the upper leather to keep the cold air from coming in; and also porous enough to let the perspiration out. Your feet are not exactly like those of any one else; and yet you expect to find at any shoe store a comfortable shoe ready-made. You expect that shoe to come close to your foot, and yet allow you to move it with perfect freedom. You expect all these good qualities, and what is more remarkable, it does not seem difficult for most people to get them. There is an old saying, "To him who wears shoes, the whole earth is covered with leather"; and although many different materials have been tried in shoemaking, leather is the only one that has proved satisfactory, for the sole of the shoe at least.

Of late, however, rubber and rubber combinations and felts and felt combinations have been used.

Most hides of which soles are made come from the large beef packing-houses or from South America. Goatskins come from Africa and India. The greater part of a hide is made up of a sort of gelatine.

This easily spoils, and therefore it has to be "tanned"; that is, soaked in tannin and water. When a man set out to build a tannery, he used to go into the woods where he could be sure of enough oak trees to supply him for many years with the bark from which tannin is made; but it has been found that the bark of several other kinds of trees, such as larch, chestnut, spruce, pine, and hemlock, will tan as well as that of oak. Tannin is now prepared in the forest and brought to the tanners, who put their tanneries where they please, usually near some large city. The hides are first soaked in water, and every particle of flesh is sc.r.a.ped away. They are laid in heaps for a while, then hung in a warm room till the hair loosens and can be easily removed, then soaked in tannic extract and water. The tannin unites with the gelatine; and thus the hide becomes leather. This process requires several months. Hides are also tanned by the use of chemicals, in what is called "chrome" tanning. This process requires only a few hours, but it is expensive.

In earlier times the shoemaker used to go from house to house with his lapstone, waxed end, awl, and other tools. The farmer provided the leather, which he had tanned from the hides of his own cattle. Now, however, manufacturers can buy the soles of one merchant, the heels of another, the box toe and stiffenings of another, and so on. In the United States there are many factories which do nothing but cut soles, or rather stamp them out with dies, a hundred or more in a minute.

These soles and also the less heavy inner soles go through machines that make all parts of them of a uniform thickness. The traveling shoemaker always hammered his sole leather to make it wear better; but now a moment between very heavy rollers answers the same purpose.

Another machine splits the inner sole for perhaps a quarter of an inch all the way around, and thus makes a little lip to which to sew the welt. A number of layers or "lifts" of leather are cemented together for the heel, and are put under heavy pressure.

The upper parts of a shoe, the "uppers," as they are called, are the vamp or front of the shoe, the top, the tip, and (in a laced shoe) the tongue. Nearly all the upper leather that shows when a shoe is on is made from the hides of cattle, calves, goats, and sheep; but besides the parts that show there are stiffeners for the box toe and the counters to support the quarters over the heel; there are linings, and many other necessary "findings," forty-four parts in all in an ordinary shoe. Much experimenting and more thinking have gone into every one of these forty-four parts; and much remembering that shoes have harder wear than anything else in one's wardrobe. The cotton linings, for instance, must be woven in a special way in order to make them last and not "rub up" when they are wet with water or perspiration. They are bleached with the utmost care not to weaken them, and they are singed between red-hot copper plates to remove all the nap.