The commercial importance of the steel pen was first manifested to our senses a year or two ago at Sheffield. We had witnessed all the curious processes of _converting_ iron into steel, by saturating it with carbon in the converting furnace;—of _tilting_ the bars so converted into a harder substance, under the thousand hammers that shake the waters of the Sheaf and the Don; of _casting_ the steel thus converted and tilted into ingots of higher purity; and, finally, of _milling_, by which the most perfect development of the material is acquired under enormous rollers. About two miles from the metropolis of steel, over whose head hangs a canopy of smoke through which the broad moors of the distance sometimes reveal themselves, there is a solitary mill where the tilting and rolling processes are carried to great perfection. The din of the large tilts is heard half a mile off. Our ears tingle, our legs tremble, when we stand close to their operation of beating bars of steel into the greatest possible density; for the whole building vibrates as the workmen swing before them in suspended baskets, and shift the bar at every movement of these hammers of the Titans. We pass onward to the more quiet _rolling_ department. The bar that has been tilted into the most perfect compactness has now to acquire the utmost possible tenuity. A large area is occupied by furnaces and rollers. The bar of steel is dragged out of the furnace at almost a white heat. There are two men at each roller. It is passed through the first pair, and its squareness is instantly elongated and widened into flatness;—rapidly through a second pair,—and a third,—and a fourth,—and a fifth.—The bar is becoming a sheet of steel. Thinner and thinner it becomes, until it would seem that the workmen can scarcely manage the fragile substance. It has spread out, like a morsel of gold under the beater’s hammer, into an enormous leaf. The least attenuated sheet is only the hundredth part of an inch in thickness; some sheets are made as thin as the two-hundredth part of an inch. And for what purpose is this result of the labours of so many workmen, of such vast and complicated machinery, destined?—what the final application of a material employing so much capital in every step, from the Swedish mine to its transport by railroad to some other seat of British industry? _The whole is prepared for one Steel-pen Manufactory at Birmingham._