Part 55

The open-hearth process consists of the purification of iron by oxidizing out the impurities and burning out the carbon of the iron until a tough and ductile steel is produced, which can be made of any desired composition by the addition of the necessary quantities of alloys just previous to tapping and pouring. The impurities in the iron are oxidized by the slag lying on top of the metal, and the burning out of the carbon, which is a very slow operation, is hastened by the addition of iron ore, the oxygen of which combines with the carbon of the iron and passes off is a gas going up the stack.

When an open-hearth furnace is ready for a charge, a variable amount of scrap, say 30 per cent of the total weight of material used for the heat, is charged into the furnace. With this scrap is charged sufficient lime or limestone to make the slag, as well as some iron ore to assist in reducing the carbon of the iron. In about two or three hours the required amount of molten iron is brought from the mixer in ladles, and poured into the furnace on top of the scrap, lime and ore.]

Molten Steel Being Poured Into Ladle.

When the scrap has all been melted, a test is taken to determine the amount of carbon remaining in the bath. Iron ore is added from time to time until the carbon in the bath has been reduced to the desired point, and the metal is sufficiently hot to pour. At this point “recarburizers” (consisting of Ferro-Manganese, Ferro-Silicon, and pig-iron, or coal) are added to get the required composition. The tap hole at the back of the furnace is opened, and the steel is allowed to run out into a ladle, the slag coming last and forming a blanket over the steel in the ladle.]

The ladle is picked up by an electric crane and carried over cast-iron moulds, which are set on cars, the steel being poured into the moulds, resulting in steel ingots. A sufficient amount of time is allowed for the steel to become chilled or set, when the cars are pushed under an electric stripper, where the moulds are removed from the ingots. After the ingots leave the stripper they are taken to the scales and weighed, and after weighing are put into the soaking pits. The pits get their name from the part they play in the heating of the steel for rolling. When the steel ingot is stripped the outside of the ingot is cool enough to hold the inside, which is still in a liquid state, and the steel is put into the soaking pits to allow the inside to settle into a solid mass, after which the ingot is reheated for rolling. The length of time in the soaking pits depends upon the size of the ingot, as the larger the ingot, the greater length of time is required to set.

When the steel is ready for rolling it is taken from the pits by overhead electric cranes, and placed into a dump buggy at the end of a roller line, which leads to the blooming mill. The dump buggy derives its name from the fact that when the ingot is placed into same in an upright position, the buggy, in order to place the ingot into a horizontal position on the roller line, dumps over, in the same way as if one were to rock too far forward in a rocking-chair, the dump buggy operating on the same principle.]

Blooming Mill and Engine.

The ingot travels down the movable-roller line to the blooming-mill rolls, which roll it down from a piece 19 inches by 23 inches to what is known as an 8 inch by 8 inch bloom, which is the size usually used in the manufacture of rails. The blooming mill derives its name from the fact that after an ingot is rolled in same it is no longer called an ingot, but a bloom.

After leaving the blooming mill the bloom travels along another roller line to the shears, where it is cut into two or three pieces, the number of pieces depending on the size of the rail which is to be rolled. The blooms are then lifted over the roller line at the shears by a transfer crane, and placed on a traveling roller line which connects with the rear of the reheating furnace. This furnace is about 35 feet long, and is so constructed that when the bloom is pushed in at the rear of the furnace, another bloom drops from the front or discharge end of the furnace.]

The Ingot Becomes a Rail.

The bloom dropping out, being sufficiently hot to roll into rails, travels along another roller line to the roughing or first set of rolls. Here the bloom is given five passes in the rolls, and is then transferred to the strand or second set of rolls, where it receives five additional passes; after this operation it is transferred to the finishing or third set of rolls, in which it is given one pass. The bloom has now been converted into a rail, and the rail travels on another roller line to the hot saw, where it is cut into 33-foot lengths, this being the standard length in this country for all rails. The rails when hot are cut by the hot saw to lengths of about 33 feet 6¹⁄₂ inches, the allowance of inches being made for shrinkage in cooling. It is difficult to believe that steel shrinks to this extent, but this is a fact, and while the rails are cooling on the hotbeds they have the appearance of being animated, as they move first one way and then the other. After the rails are on the hotbed a sufficient length of time to cool, they are taken from the hotbed and placed on a traveling roller line, which takes them to an endless chain conveyor. The statement that rails are put on hotbeds for cooling seems paradoxical, but the hotbeds are so called because the rails are placed on them while hot, and are left there until they have cooled.

The endless-chain conveyor places the rails on another bed, from which they are picked up by an electric crane and distributed to the straightening presses, where all burrs (which have been caused by the hot-sawing operation) are removed before the rails are straightened. After straightening they are transferred to drill presses, where they have holes drilled into them for the accommodation of the splice bar, after which they are placed on the loading docks.]

Who Made the First Felt Hat?

The felt hat is as old as Homer. The Greeks made them in skull-caps, conical, truncated, narrow- or broad-brimmed. The Phrygian bonnet was an elevated cap without a brim, the apex turned over in front. It is known as the “cap of liberty.” An ancient figure of Liberty in the times of Antonius Livius, A.D. 115, holds the cap in the right hand. The Persians wore soft caps; plumed hats were the headdress of the Syrian corps of Xerxes; the broad-brim was worn by the Macedonian kings. Castor means a beaver. The Armenian captive wore a plug hat. The merchants of the fourteenth century wore a Flanders beaver. Charles VII, in 1469, wore a felt hat lined with red, and plumed. The English men and women in 1510 wore close woolen or knitted caps; two centuries ago hats were worn in the house. Pepys, in his diary, wrote: “September, 1664, got a severe cold because I took off my hat at dinner”; and again, in January, 1665, he got another cold by sitting too long with his head bare, to allow his wife’s maid to comb his hair and wash his ears; and Lord Clarendon, in his essay, speaking of the decay of respect due the aged, says “that in his younger days he never kept his hat on before those older than himself, except at dinner.” In the thirteenth century Pope Innocent IV allowed the cardinals the use of the scarlet cloth hat. The hats now in use are the cloth hat, leather hat, paper hat, silk hat, opera hat, spring-brim hat, and straw hat.

What Is the Hottest Spot on Earth?

The hottest regions on earth is said to be along the Persian Gulf, where little or no rain falls. At Bahrein the arid shore has no fresh water, yet a comparatively numerous population contrive to live there, thanks to the copious springs which break forth from the bottom of the sea. The fresh water is got by diving. The diver, sitting in his boat, winds a great goat-skin bag around his left arm, the hand grasping its mouth; then he takes in his right hand a heavy stone, to which is attached a strong line, and thus equipped he plunges in, and quickly reaches the bottom. Instantly opening the bag over the strong jet of fresh water, he springs up the ascending current, at the same time closing the bag, and is helped aboard. The stone is then hauled up, and the diver, after taking breath, plunges in again. The source of the copious submarine springs is thought to be in the green hills of Osman, some 500 or 600 miles distant.

Where Do We Get Ivory?

Ivory is a hard substance, not unlike bone, of which the teeth of most mammals chiefly consist, the dentine or tooth-substance which in transverse sections shows lines of different color running in circular arcs. It is used extensively for industrial purposes and is derived from the elephant, walrus, hippopotamus, narwhal, and some other animals. The ivory of the tusks of the African elephant is held in the highest estimation by manufacturers; the tusks vary in size, ranging from a few ounces in weight to 170 pounds. Holtzapffel states that he saw fossil tusks on the banks of rivers of Northern Siberia which weighed 186 pounds each. Ivory is simply tooth-substance of exceptional hardness, toughness, and elasticity, due to the firmness and regularity of the dentinal tubules which radiate from the axial pulp-cavity to the periphery of the tooth.

How Did Trial by Jury Originate?

~WHY JURIES HAVE TWELVE MEN~

A jury consists of a certain number of men selected according to law and sworn to inquire into and determine facts concerning a cause or an accusation submitted to them, and to declare the truth according to the evidence. The custom of trying accused persons before a jury, as practised in this country and England, is the natural outgrowth of rudimentary forms of trial in vogue among our Anglo-Saxon ancestors. The present system of trial by jury is the result of a gradual growth under the English Common Law. There is no special reason why twelve is the usual number chosen for a complete jury except the necessity for limiting the number. In a grand jury the number according to law must not be less than twelve nor more than twenty-three, and twelve votes are necessary to find an indictment. The ancient Romans also had a form of trial before a presiding judge and a body of judices. The right of trial by jury is guaranteed by the United States Constitution in all criminal cases, and in civil cases where the amount in dispute exceeds $20. A petit or trial jury consists of twelve men, selected by lot from among the citizens residing within the jurisdiction of the court. Their duty is to determine questions of fact in accordance with the weight of testimony presented and report their finding to the presiding judge. An impartial jury is assured by drawing by lot and then giving the accused, in a criminal case, the right to dismiss a certain number without reason and certain others for good cause. Each of the jurymen must meet certain legal requirements as to capacity in general and fitness for the particular case upon which he is to sit, and must take an oath to decide without prejudice and according to the testimony. A coroner’s jury or jury of inquest is usually composed of from six to fifteen persons, summoned to inquire into the cause of sudden or unexplained deaths.

Can Animals Foretell the Weather?

Certain movements on the part of the animal creation before a change of weather appear to indicate a reasoning faculty. Such seems to be the case with the common garden spider, which, on the approach of rainy or windy weather, will be found to shorten and strengthen the guys of his web, lengthening the same when the storm is over. There is a popular superstition that it is unlucky for an angler to meet a single magpie, but two of the birds together are a good omen. The reason is that the birds foretell the coming of cold or stormy weather, and at such times, instead of searching for food for their young in pairs, one will always remain on the nest. Sea-gulls predict storms by assembling on the land, as they know that the rain will bring earthworms and larvæ to the surface. This, however, is merely a search for food, and is due to the same instinct which teaches the swallow to fly high in fine weather, and skim along the ground when foul is coming. They simply follow the flies and gnats, which remain in the warm strata of the air. The different tribes of wading birds always migrate before rain, likewise to hunt for food. Many birds foretell rain by warning cries and uneasy actions, and swine will carry hay and straw to hiding-places, oxen will lick themselves the wrong way of the hair, sheep will bleat and skip about, hogs turned out in the woods will come grunting and squealing, colts will rub their backs against the ground, crows will gather in crowds, crickets will sing more loudly, flies come into the house, frogs croak and change color to a dingier hue, dogs eat grass, and rooks soar like hawks. It is probable that many of these actions are due to actual uneasiness, similar to that which all who are troubled with corns or rheumatism experience before a storm, and are caused both by the variation in barometric pressure and the changes in the electrical condition of the atmosphere.

Nearest Approach Ever Made to Perpetual Motion in Mechanics.

An inventor has patented a double electric battery which seems to come exceedingly near to perpetual motion. Instead of using the zinc battery, he professes to have hit upon a solution which makes a battery seven times as powerful as the zinc battery, with absolutely no waste of material. The power of the battery grows gradually less in a few hours of use, but returns to its original unit when allowed to rest a few hours. He has two batteries so arranged that the power is shifted from one to the other every three hours. A little machine has been running for some years in the patent office at New York. Certain parts of the mechanism are constructed of different expansive capacities, and the machine is worked by the expansion and contraction of these under the usual variations of temperature. In the Bodleian Library at Oxford there is an apparatus which has chimed two little bells continuously for forty years, by the energy of an apparently inexhaustible “dry-pile” of very low electrical energy. A church clock in Brussels is wound up by atmospheric expansion induced by the heat of the sun. As long as the sun shines this clock will go till its works wear out. Mr. D. L. Goff, a wealthy American, has in his hall an old-fashioned clock, which, so long as the house is occupied, never runs down. Whenever the front door is opened or closed, the winding arrangements of the clock, which are connected with the door by a rod with gearing attachments, are given a turn, so that the persons leaving and entering the house keep the clock constantly wound up.

Do Plants Breathe?

Plants, like animals, breathe the air; plants breathe through their leaves and stems just as animals do by means of their respiratory organs. When a young plant is analyzed it is found to consist chiefly of water, which is all removed from the soil; there is about 75 per cent or more of this fluid present, and the rest is solid material. Of this latter by far the most abundant constituent is carbon, almost every atom of which is removed from the atmosphere by the vital action of minute bodies contained in the green leaves. The carbon is taken into the plant as carbonic acid gas. Plants also absorb oxygen, hydrogen, and nitrogen from the atmosphere in different quantities through their leaves, and also by means of their roots. These new products stored are in turn used in building up the different organs of the plant. Plants give off used-up moisture through their leaves, just as animals perspire through the pores of their skins. Calculations have been made as to the amount of water thus perspired by plants. The sunflower, only 3¹⁄₂ ft. high, with 5,616 square inches of surface exposed to the air, gives off as much moisture as a man.

What Depth of Snow Is Equivalent to an Inch of Rain?