“The close of the Civil War found the iron-making world in full possession of the Bessemer process of converting that metal into steel.... The variety of uses for this metal is absolutely beyond enumeration.... Within the space of a generation we have increased our iron consumption fourfold.... This is the age of power. Man has changed his economic and social conditions in that he has harnessed the forces of nature to make them do his work. Our main dependence, thus far, has been upon fuel, chiefly coal. The power in the form of the steam generated in the boiler is kept imprisoned in iron pipes until released in the steel cylinder, where a steel piston drives forward a steel rod, which communicates the force to a steel fly wheel, turning on a steel shaft, and sending the power away to various places where man wishes to use it.
“Portable engines, entirely made of iron and steel, are drawn about the country, or move themselves and carry
loads.... The dynamo rests upon a heavy iron frame and swings its iron arms and iron magnets through space, whence it mysteriously winds out power.... The second of the great iron uses is to be found in the machines driven by the power that man has learned to harness.... Transport is the third member of the mechanical trinity which goes with power and machines to make the present epoch. For a long time the railways consumed half of man’s total iron product. The street railway of the city is also a heavy consumer. The elevated railway is nothing but a bridge spanning the city in all directions, and the subway, its latest rival, is but a steel tunnel burrowing beneath the ground. In the country, the erection of the trolley lines is now giving us a second set of railways, and even the poles are coming to be made of iron. Half a century ago iron ships began to be common, a quarter of a century ago the ship-builder turned to steel, and now there is almost nothing else afloat upon the high seas.... Our structures are becoming more and more dependent upon the products of the blast furnace and the steel mills. Our fathers contented themselves with brick and stone and wood. The limitation of wooden beams and the cheapness of Bessemer steel caused that material to be used in heavy structures in a limited way, and as wood increased in value and knowledge of the use of steel increased, we now see the modern sky scraper in which wood is eliminated and steel the absolute essential....
“It is therefore natural to expect that the blast furnace should be among the most thoroughly organized and most highly developed pieces of mechanism yet devised. It is certainly the most fearful of all man’s creations, and considering the character of the process which goes on within it and its unapproachable heat, it is under a wonderful degree of control. At the present time, the blast furnaces are a hundred feet high, consist of a great iron stack lined with some nonfusible material, and when in operation are filled
from top to bottom with roaring fire. Into their fiery throats are fed alternately small carloads of coke and iron and limestone, and from the bottom there flows away at intervals two molten streams—one the precious iron upon which our civilization rests; the other the useless slag, to be got rid of in the cheapest possible way.... The burning of this modern furnace takes place under a forced draught of air blast from eight to twenty pounds per square inch. This pressure serves to drive the air upward through the hundred-foot mass which burns within the furnace. Otherwise, the fire would smother. The gas which results from the imperfect combustion within the furnace is a most valuable by-product and serves a valuable purpose in promoting the furnace operation, and sometimes leaves a product to sell. A part of the gas is taken to the boilers, where it generates power for the blowing engines. Another part of it is used in the so-called stoves to heat the air blast on its way to the furnaces.”
The iron obtained by this Bessemer process, by which the carbon and other impurities are burned out, is, when it leaves the converter and cools, merely soft, malleable iron, and to transform it into steel there must be re-inserted a small but fixed and definitely determined amount of carbon. “Steel,” says J. Russell Smith, “is simply a mixture of iron with a small amount of carbon, very intimately and evenly associated in its mass. The carbon content of steel varies from .40 per cent to 1.50 per cent. Steel making is, therefore, a process of mixing carbon and iron in proper proportions. Inasmuch as it cannot be made satisfactorily in a puddling furnace, by reducing the carbon to a proper point and then stopping the furnace, it has been found necessary to burn the carbon all out, making wrought iron, and then working it back to steel by recarbonizing under such conditions that the carbon can be controlled. The iron, after having all of its carbon and other impurities burned out by the Bessemer process, is raised to steel by having thrown into it spiegel
iron or ferro manganese. Both are rich in manganese and carbon. As the iron content of the Bessemer converter is known and the content of the spiegel iron is known, the carbon in the steel is under perfect control. The workman watching the flames cuts off the blast at the moment when the changing color tells him the carbon is gone. The carbon of the added material makes steel, and the manganese gives to the steel a toughness needed to make it stand the strain of being rolled into desired shapes while red-hot, without breaking....
“The steel for the greater industries is shaped in a rolling mill. It comes from the Bessemer or open-hearth converter molded into a great billet like a piece of a large wooden beam, and this billet is carried red-hot to a so-called soaking pit, where the tongues of a flame from a gas-fire keep it heated until it is ready to start on its journey through the mills. This soaking pit is the starting point of many roads through the mill. It goes off in one direction, and successive rollers squeeze it, crush it, and lengthen it into steel rails, in which form it emerges a thousand feet away. Other sets of rolls make the billet into flat beams for bridges or elevated railways. A third set of rolls, also starting near the soaking pits, send the product out of the distant door of the steel mill in the form of great flat plates to make the boiler of a locomotive, or a marine engine, or the sides of a steamship, and yet other sets of rollers will make square rods which finally pass under heavy shears and are chopped into pieces called billets or blooms. These pieces of steel are the raw material for other mills which may make wire, nails, or manufacture steel of any other of a thousand forms. Some billets are as big as cord wood, some no larger than lead pencils—thus it passes out into the manifold world of manufacture.”
VII. THE TEXTILE INDUSTRY.
Cotton manufacturing is an important illustration of the growth in the textile industries of the world during the period in which the use of machinery has multiplied the producing power of man in the industrial lines. In all lines of textile manufacture the growth has been rapid, but especially so in cotton, which has made greater gains in the work of supplying man with the necessary requirements of life, in clothing for his body and the comforts of life, than other branches of the textile industries and than many other branches of manufacture. Mulhall estimates the consumption of cotton by all nations at 303 million pounds in 1800 and 5,900 million pounds in 1896; wool, 460 million pounds in 1800 and 2,400 million pounds in 1896; flax, 600 million pounds in 1800 and 200 million pounds in 1896; silk, 30 million pounds in 1800 and 50 million pounds in 1897. It will be seen from these estimates that the growth in consumption of cotton has been far in excess of that of any other of the important fibers. Cotton consumption in 1896 was, according to these figures, 5,900 million pounds, against 303 million in 1800, or practically 20 times as much in 1896 as in 1800, while wool consumption is set down at 2,400 million pounds in 1896, against 460 million in 1800, or only about 5 times as much in 1896 as in 1800; while in the other materials used in textile manufactures the growth has been much less than that of cotton.