To Pittsburgh, centre of the steel industry, comes a large portion of the ore shipped from the Great Lakes. Ore destined for the Pittsburgh furnaces is brought from the Lake ports by the Bessemer Lake Erie, another Corporation subsidiary, with its two hundred and five miles of main line, the third longest and perhaps the best known of the Steel Corporation roads. The Duluth, Missabe & Northern holds first place among these roads in respect to mileage, two hundred and forty-seven miles, with the Elgin, Joliet & Eastern second, two hundred and eleven miles, and the Duluth & Iron Range fourth, one hundred and ninety-seven miles. The total trackage of the U. S. Steel roads, including sidings, branches, switches, and yard track, is 3,774 miles, every yard of it maintained in prime condition and absolutely modern. A line drawn from New Orleans to St. Louis, thence to Kewanee, Ill., through Minneapolis and north to the Canadian border would about form the western boundary of the big Corporation’s manufacturing and mining activities. The northern boundary would be the Canadian border (except for one plant at Hamilton, Ont.) with the Atlantic and the Gulf of Mexico forming the east and south boundaries. Half the United States! And another plant is started in Canada. All over this vast area are scattered the Corporation’s plants, but nowhere are they so thickly clustered as around Pittsburgh, the steel city of the world. Here the biggest of the subsidiary companies, Carnegie Steel, has its headquarters, and here, too, is the home of the National Tube, American Sheet and Tin Plate, and American Bridge companies. All the Carnegie plants are in or near Pittsburgh, as are the major part of the plants of the National Tube Co., but the Tin Plate and Bridge companies reach out in many directions. The Chicago territory provides a home and a market for the Illinois Steel Co. with its “South Works” plant at South Chicago and the Indiana Steel Co., which operates the great Gary plant at Gary. The American Steel & Wire Co. has its head office at Cleveland, but its plants are scattered over a great many states from Illinois to Massachusetts and down to Alabama, and it has a plant at Hamilton, Ont. All over Pittsburgh and its environs are to be seen the stacks of the blast furnaces of the Corporation and other steel companies in which the ore is transformed into pig iron, the first step in the manufacture of steel. These furnaces, usually built in “batteries” several together, are immense ovens of steel and firebrick in which a temperature of more than 3,000 degrees is generated and in this terrific heat the ore, fluxed with limestone, is melted and converted into iron. From the ground to the tops of the furnaces run “skips” or buckets on inclined tracks, which carry the ore to their mouths, where, with a mixture of coke and limestone, it is dumped.