were governed by this fuel; hence eastern Pennsylvania was the main producing district. The supplies of ore near this region were smelted with its anthracite coal, and Philadelphia was the central market. Proximity to the seaboard made foreign competition easy, except so far as it was hampered by the tariff duties; and the very existence of the iron industry was felt to depend on the maintenance of protection. For some time after the close of the Civil War this dominant position of anthracite iron was maintained. In 1872, when the systematic collection of detailed statistics began, out of a total production of two million five hundred thousand tons, one half was smelted with anthracite coal, a third with bituminous coal or coke, the remainder with wood (charcoal). The use of soft coal, which had begun before 1860, became rapidly greater. Already in 1872 it was important, and from year to year it grew. In the periodic oscillations between activity and depression, which mark the iron trade more distinctively than any other industry, anthracite iron shrank sensitively in the slack periods, and barely regained its own in the succeeding periods of expansion. Bituminous or coke iron, on the other hand, held its own during the hard times, and advanced by leaps and bounds with each revival of activity. In 1875, for the first time, its output exceeded that of the rival eastern fuel, and since that date the huge advance in the iron product of the United States has been dependent on the use of coke. Indeed, the use of anthracite alone began to shrink at a comparatively early date. It soon ceased to be used on any large scale as the sole fuel, coke being mixed with it for use in the blast furnace. The production of iron with anthracite coal only has shrunk to insignificant dimensions. What is classed as "anthracite iron" is smelted with a mixture of coke and hard coal; and, even with the aid of the coke, this means of reducing the ore has come to be of less and less importance. Virtually, anthracite coal has been displaced as an iron-making fuel.1

This change is easy of explanation. It is the inevitable result of the greater plenty and effectiveness of coke; and it has been 1 The production of pig iron by fuel at quinquennial intervals is given in the table on page 196. By way of illustrating the trend over a long period, the year

powerfully promoted by the rapid development of the United States west of the Appalachian chain, and the nearness of the coke region to this growing market. Anthracite, at best, is an obdurate fuel. At the same time its strictly limited supply and the cleanliness and freedom from smoke, which make it an ideal domestic fuel, have maintained its price at a comparatively even level. On the other hand, the almost unlimited supplies of bituminous coal and the feverish competition in opening coal lands and marketing their product have caused an almost uninterrupted fall in its price. Coke has proved, ton for ton, a better fuel than anthracite; the supplies of bituminous coal available for coking are virtually limitless, and the processes of coking have been applied on a huge scale and with tireless energy.

Pittsburg, long ago seen to be destined to become a great iron center, is situated in the heart of the region where coking coal is plentiful. To this point the iron industry has converged, attracted first by cheap fuel and soon by other geographical

1855 has been taken as the starting point. The figures, as in the previous table, indicate thousands of gross tons.

[In 1906 the pig iron smelted with anthracite or anthracite and coke amounted to 1,560,686 tons; that smelted with charcoal amounted to 433,000 tons; and that smelted with bituminous coal or coke amounted to 23,313,498 tons. - ED.]

advantages of the region, its easy access to the growing western country, and the added opportunities of securing superabundant quantities of the best ore. Pennsylvania has remained the greatest iron-producing state in the Union; but since 1880 it has been western Pennsylvania, and no longer eastern, which has secured to the state its leading position. Since 1890 this district alone has yielded steadily 40 per cent of the enormous iron product in the country; and it is here, and in the other western districts in which the same industrial forces have been at work, that we have to study the conditions on which the growth of the iron industry has depended.

The westward movement has been spoken of in the preceding paragraph as affected by the geographical distribution of the fuel. But it has been no less affected by the distribution of the ore supply, and the effect of this in turn has rested on the revolution wrought in the iron trade by the Bessemer process.

The first inventions which made plentiful the iron indispensable for all our material civilization were Cort's processes for puddling and rolling. Through the first three quarters of the century this was the mode in which the world got its supply of the metal in tough form, usable where heavy strain must come on it. The processes involved at once a considerable plant, complex machinery, and strenuous exertion by skilled and powerful laborers, conditions which during this period promoted the supremacy of the British iron trade. In the decade 18601870 the process devised by Sir Henry Bessemer, to which his name attaches, began a second revolution in the iron trade. That process involves a still larger plant and still more elaborate machinery; and it applies machinery more fully to the elimination and subsequent replacing of the carbon on which the toughness of the iron depends. By the new methods the production of mild steel that is, tough iron became possible on a vastly greater scale. Bessemer steel has displaced puddled iron in most of its uses. Not only this: the cheap and abundant supply, besides filling needs previously existing, has opened vistas for new plant, machinery, durable instruments of

production of all sorts. The first great application of the method was to rails, where the elastic and impact-sustaining steel enabled railway engines and cars to be doubled and quadrupled in size, and to become more efficient in even greater ratio. Gradually and steadily new and wider uses were found for the cheap steel. From great ships down to everyday nails, almost every iron instrument became cheaper and better. Wood was supplanted by steel for a variety of uses, and the slow-growing and easily exhausted stores of timber were reënforced by the well-nigh limitless deposits of ore in the earth's crust. A new domain in nature's forces was opened to man.

But the Bessemer process depends for its availability on special kinds of ore and pig iron, such as are well-nigh free from sulphur and especially from phosphorus. Variants of the process, free from this limitation, have indeed been applied on a great scale, especially in Germany, where supplies of non-phosphoric ore are not readily available. But the original Bessemer process remains the most effective and the most economical. Ores adapted to it have hence become doubly valuable, and the accessible parts of the earth have been scoured to find them. The deposits of Great Britain in Cumberland and Lancashire contained important supplies, yet not in quantity adequate to the new demand; and the Spanish fields of Bilboa, on the Bay of Biscay, have become an indispensable supplement for the British ironmasters. In the United States, also, some of the sources previously used in the region east of the Appalachian chain proved to be available, such as the famed deposits, once unique in their ease of working, in the Cornwall hills of eastern Pennsylvania. But the greater part of the eastern ores were too highly charged with phosphorus, or for other reasons unavailable. Here, as in Great Britain, a distant source of supply was turned to. The Lake Superior iron region, long known to explorers and geologists, suddenly sprang into commanding place. Here were abundant and super-abundant supplies of rich and properly constituted ore. These and the equally abundant coal of Pennsylvania were brought together, the iron made from them was converted into steel by the Bessemer process; and

thus only became possible the astounding growth in the production of iron and steel in the United States.

The iron mines of the Lake Superior region stretch in widely separated fields along the lake, from the middle of its southern shore to its extreme northwestern end. Intercalated between them is the great copper-bearing peninsula, whose rich yield of that metal has affected the copper trade in the same manner and almost in the same degree as the iron mines have the iron trade. At the extreme eastern end is the Menominee iron field, usually described in connection with the other Lake Superior fields, yet differing from them in important respects. The ore of the Menominee district is easily mined; and it is easily shipped, finding an outlet by the port of Escanaba on Lake Michigan, and thus traversing a much shorter journey to its eastern markets than that from the Lake Superior mines proper. But it is usually of non-Bessemer quality, and hence can play no considerable part in the most characteristic effects of the new developments. The great Bessemer ore fields of Lake Superior are four in number, in geographical order from east to west, the Marquette, the Gogebic, and the neighboring Vermilion and Mesabi. As it happens, the geographical order has been also, in the main, the order of exploitation. The easternmost, the Marquette, finding its outlet by the port of that name, was the first to be worked on a great scale. Even before the Civil War mining and smelting had begun; and, as the Bessemer process was more and more largely used, especially after 1873, it was exploited on a larger and larger scale. Here began the digging on a great scale, and the transportation to great distance, of Bessemer ore. After a considerable interval the second field, the Gogebic, began to be worked, in 1884. Lying some two hundred miles further west, along the boundary line between Wisconsin and Michigan, and finding its outlet by Ashland, on the southern shore of Lake Superior, here was found perhaps the richest and purest Bessemer ore. At about the same time, in 1884, began the development of the most distant of the fields, the Vermilion, lying to the north of the extreme end of Lake Superior, in the state of Minnesota, close to the Canada frontier.