592 THE POPULAR SCIENCE MONTHLY. 



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 Sep- 

 tember, 184G, the New England Iron Company, at Providence, R. I., 

 made their first rail. Railroad iron was rolled at Phcenixville, 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 finish- 

 ing rolls." Their general relations to each other were quite simi- 

 lar 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 promi- 

 nent 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 rolling- 

 mill 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 



* For the manufacture of heavy " bar iron " and " structural shapes " (" beams," " chan- 

 nel bars," " angle" and "tee iron") the "three-high rolls" are a development of American 

 practice due to the ingenuity and practical sagacity of the brothers John and George Fritz, 

 who erected the first mill of this kind for rolling rails at the Cambria Iron Works at 

 Johnstown, Pa., in 1858. Such were the manifest advantages of their system that it was 

 at once adopted by many of the larger rolling-mills, although as late as 1865 there were a 

 few mills rolling rails on the old " two-high trains." I well remember advising in 1 862 the 

 removal of an ancient " eighteen-inch two-high rail train," and the putting in its place of a 

 ' twcnty-onc-inch three-high train," and the opposition and ridicule over which that advice 

 finally triumphed. 



