The Wonder Book Of Knowledge Part 56

_Copyright by Underwood & Underwood, N. Y._]

[Ill.u.s.tration: ARMOR PLATE FORGING PRESS

The Bethlehem Steel Company installed this great hydraulic press to replace a 135-ton steam hammer, which was abandoned because the shock of its blow disturbed the alignment of the big machines in nearby shops.

This press is the largest of its kind in the world, having a capacity of 15,000 tons, induced by pressure as much as 7,000 pounds per square inch in its two hydraulic cylinders of over 50-1/2 inches diameter.]

[Ill.u.s.tration: MAKING ARMOR PLATE

View of the armor plate machine shop at the Bethlehem Steel Company. The varied and complex machining required on armor plate demands tools of enormous size and strength as well as varied purpose. In this shop the different groups of armor are a.s.sembled in the position they will occupy on the vessel for which they are intended, and inspected before s.h.i.+pment.]

[Ill.u.s.tration: _Courtesy of Bethlehem Steel Co._

FORGING

One-piece, 90-degree, double-throw crank shaft for 5,400 H. P. gas engine. Diameter of shaft, 37 inches, with 10-inch hole. Length over all, 25 feet 5 inches. Crank webs, 16-3/8 inches thick, 6 feet 1-1/2 inches long, 4 feet 1 inch wide. Forged weight of shaft, 133,400 pounds.

Finished weight, 83,855 pounds.]

We have always said "a white elephant" when we have meant something we didn't know what to do with, since the King of Siam first sent a white elephant to a courtier whose fortune he wished to destroy.

What do We Mean by "Deviation of the Compa.s.s"?

When people speak of "deviation of the compa.s.s" they mean the difference of a s.h.i.+p's compa.s.s from the magnetic meridian, caused by the near presence of iron. In iron s.h.i.+ps the amount of deviation depends upon the direction, with regard to the magnetic meridian, in which the s.h.i.+p lay when being built. It is least when the s.h.i.+p has been built with her head south. Armor-plated s.h.i.+ps should be plated with their head in a different direction from that in which they lay when built.

The mode now generally employed to correct deviation is by introducing on board s.h.i.+p ma.s.ses of iron and magnets to neutralize the action of the s.h.i.+p's magnetism so far as possible.

Compa.s.ses are sometimes carried on masts in iron vessels as a means of removing them from the disturbing influence of the iron of the hull. In this position they serve as standards of comparison for the binnacle compa.s.s.

Wooden s.h.i.+ps are also affected, though in a far less degree, by the direction in which they lie when building.

The Story in the Making of a Pair of Shoes[46]

The covering and protection of the feet has been a necessity in all but the warm climates for very many centuries, various articles being used for this purpose. Leather is now very generally employed, though wood is often used in Holland and France and paper in China and j.a.pan. The moccasin of the American Indian was made of untanned deer skin. The first historical mention of a shoe is in the Old Testament, where Abraham refused to take as much as a "shoe-latchet" from the King of Sodom. This probably meant a sandal, leather strapped to the foot, though the Jews wore shoes as well, and both shoes and sandals were worn in Greece and Rome. Both in ancient and modern times the styles of shoes worn have varied greatly, fas.h.i.+on taking hold of them. In the reigns of the English kings Henry I and Stephen, the people of the court wore shoes with long points stuffed with tow and made to coil like a ram's horn, and by the time of Richard II the points had grown so long as to reach the knee, to which they were fastened by silver or gold chains. In the eighteenth century ladies wore shoes with absurdly high heels, a ridiculous fas.h.i.+on which has come back within our own times. An improvement which was adopted in the early nineteenth century was that of making shoes right and left. Boots, which have at times been much worn, are a variety of shoe lengthened to protect part of the legs.

Until within a recent period the trade of shoemaker was an active one, all boots and shoes being made by hand. At the present time, however, the old-time shoemaker, with his bench, lapstone, last and awls has almost gone out of business, except as a cobbler, mending instead of making having become his usual occupation. In his place has come the factory hand, nearly all footwear being now a product of machinery, and this of greatly varied and effective character. In this form shoemaking has become a thriving industry in New England and in some other parts of the United States. This method has greatly decreased the cost of shoes, invention having so hastened and cheapened all its processes that the number of shoes that it would take an old-time shoemaker a year to make can be turned out in a few hours by modern machinery.

Shoemaking by Machine.

The variety of inventions used in shoe factories is rather bewildering, every one of the many processes having a machine of its own, and each of these doing its work with admirable precision. We can name here only the more important of these implements.

First comes the clicking machine. This has a cutting board resembling that used by the hand workmen. Over this is a beam containing a cutting die under which the leather is pa.s.sed. At every descent of the die a piece of leather is cut out of the skin of the size and shape needed for the upper leather of a shoe. Thus in an instant is done what was slowly done by a sharp knife moved around a pattern in the old method.

[Ill.u.s.tration: IN THE DAYS OF THE AWL, LAPSTONE AND HAMMER]

[Ill.u.s.tration: AMAZEEN SKIVING MACHINE]

[Ill.u.s.tration: CROSS-SECTION OF GOODYEAR WELT SHOE, SHOWING THE DIFFERENT PARTS AND THEIR RELATION TO EACH OTHER]

[Ill.u.s.tration: INSOLE TACKING MACHINE]

[Ill.u.s.tration: IDEAL CLICKING MACHINE]

[Ill.u.s.tration: DUPLEX EYELETING MACHINE]

[Ill.u.s.tration: ENSIGN LACING MACHINE]

[Ill.u.s.tration: REX PULLING-OVER MACHINE]

[Ill.u.s.tration: REX UPPER Tr.i.m.m.i.n.g MACHINE]

[Ill.u.s.tration: CROWN TIP PUNCHING MACHINE]

[Ill.u.s.tration: BED LASTING MACHINE]

[Ill.u.s.tration: GOODYEAR UNIVERSAL INSEAM Tr.i.m.m.i.n.g MACHINE]

[Ill.u.s.tration: TACK-PULLING AND RESETTING MACHINE]

[Ill.u.s.tration: CONSOLIDATED HAND METHOD WELT LASTING MACHINE]

[Ill.u.s.tration: IMPROVED SOLE LAYING MACHINE]

[Ill.u.s.tration: STAR CHANNEL CEMENTING MACHINE]

[Ill.u.s.tration: GOODYEAR AUTOMATIC SOLE LEVELING MACHINE]

[Ill.u.s.tration: AMERICAN LIGHTNING NAILING MACHINE]

The piece of leather thus cut out is next pa.s.sed under the skiving machine, which shaves down its edges to a bevel, the thinned edge being then folded, after which the toe caps are pa.s.sed through a punching machine which cuts a series of ornamental perforations along the edge of the cap. The linings of the shoe are then prepared and put in place and the whole goes to the st.i.tchers, by which all the parts of the upper are united. This is done by a range of machines, which perform the varied operations with wonderful rapidity and accuracy. The eyelets are next added by a machine which places them in both sides of the shoe at the same time and directly opposite each other, this operation finis.h.i.+ng the upper part of the shoe.

The sole leather portions of the shoe pa.s.s through another series of machines, being cut from sides of sole leather by the dieing-out machine, cut to exact shape by the rounding machine and to exact thickness by the splitting machine, and then toughened by pa.s.sing under a heavy rolling machine. These and other machines complete the soles and heels, which are finally sent to the making or bottoming room, where the completed shoe uppers await them.

The first process here is that of the ensign lacing machine, which puts a strong twine through the eyelets and ties it in an accurate manner.

This is done very swiftly and exactly, its purpose being to hold the parts of the shoe in their normal position while the shoe is being completed. The last, made of wood, is now put in place and tacked fast by the insole tacking machine, when the upper is placed over it and fastened by two tacks to hold it in place. Then comes the pulling-over machine, the pincers of which draw the leather securely against the wood of the last, to which it is fastened by other tacks. These tacks in the upper are driven only part way in, so that they may be easily drawn out when no longer needed.

The welt lasting machine next takes the job in hand, it being almost human-like in the evenness and tightness with which it draws the leather around the last, other tacks being driven partly in to hold it in place.

A second lasting machine of different kind, draws it around the toe and heel. Then comes the upper tr.i.m.m.i.n.g machines, which cuts away the surplus parts of the leather, the Rex pounding machine, which hammers it around the heel, the tack pulling machine which removes the lasting tacks and puts in others to hold the new placed leather, and the upper stapling machine, which forms a little staple fastening from wire which securely holds the shoe upper to the channel lip of the insole.

The shoe is now ready to receive the welt, a narrow strip of prepared leather which is sewed along the edge of the shoe and holds all its parts firmly together. This used to be one of the most difficult tasks in hand-work, but is done rapidly and exactly by this machine. After this all protruding parts of the welt and upper are trimmed off by another machine, the insole tack pulling machine removes all the remaining temporary tacks, and the welt-beating and slas.h.i.+ng machines beat the welt with little hammers till it stands out evenly from the side of the shoe.

It may seem as if the number of machines engaged in this work are almost beyond number, but there are nearly as many more to come. In fact, a factory shoe in many cases is not completed until 170 machines and 210 pairs of hands have taken part in putting it together and getting it into shape for the wearer, and each of these machines works with an accuracy which no hand-work can equal. We have so far witnessed the a.s.sembling of the several parts of the shoe into one connected whole.