Page:Popular Science Monthly Volume 38.djvu/610

592 May, 1846, the Boston Rolling Mill made its first T rail, and on the 19th of June, 1844, the rolling-mill of Cooper & Hewitt, at Trenton, N. J., commenced rolling rails. About the 1st of September, 1846, the New England Iron Company, at Providence, R. I., made their first rail. Railroad iron was rolled at Phœnixville, Pa., in November, 1846, and about the same time at the Great Western Iron Works at Brady's Bend, and at the Lackawanna Iron Works at Scranton, Pa. Rails were also rolled, early in 1847, at the Bay State Iron Works in Massachusetts; in January, 1848, at the Rough-and-Ready Rolling Mill at Danville, Pa., and in the same year at Safe Harbor, Pa., and at Avalon, Md. Some few other mills rolled rails prior to 1850, but at the beginning of that year, owing to the severity of foreign competition, only two out of the fifteen rail mills in this country were in operation.

The rail trains in all the above-named mills were "two high" (that is, one roll above another in pairs), and a general idea of the forms of the several "grooves" or "passes" in the rolls used in a two-high rail train may be derived from an inspection of Fig. 46. A two-high rail train comprised two pairs of rolls, one pair being called the "roughing rolls" and the other "the finishing rolls." Their general relations to each other were quite similar to the rolls of the "bar-mill," shown in Fig. 45.

In Fig. 46, A represents the five "passes" in the "roughing rolls," and B the six in the "finishing rolls." The progress of the metal was from left to right, through each of the "passes" in each roll successively. We have no space to describe in detail the peculiar features of the three-high train; but its more prominent peculiarity consisted in the fact that there were three rolls in each pair of housings, and that the "rail," or other form of bar being rolled, was passed between the middle and "bottom roll" and returned between the middle and "top roll," and received compression and extension at each "pass."

Fig. 47 gives a very life-like view of the interior of a rollingmill as constructed about the year 1855. It will be noted that the "trains of rolls" are all "two-high," and that the building is evidently constructed of wood; and the large number of men employed is also a conspicuous feature. To those at all familiar