AMERICAN INDUSTRIES SINCE COLUMBUS. 5g7 



important improvements in " three-high " mills, embracing what 

 is known as the " feed-roll " and " hanging guides." In 1864 Ber- 

 nard Lauth patented the well-known form of " three-high mill " 

 (often called " Lauth's mill ") for rolling boiler plate and sheet 

 iron. In 1872 James Moore and John Fritz patented a "three- 

 high train," having a fixed middle roll and an adjustable top and 

 bottom roll ; and in the latter part of the same year George Fritz 

 patented " feeding tables having driven rolls " for " three-high 

 trains." 



In December, 1873, James Moore, William George, and Alex- 

 ander L. Holley patented a " three-high blooming train," having 

 an adjustable middle roll. The first mill of this kind was made 

 by James Moore, of Philadelphia, and was put at work in the 

 Bessemer Steel Works at Troy, N. Y., by the late A. L. Holley, 

 who was then manager of these works. 



Among the more recent improvements in the manufacture of 

 iron and steel the use of gaseous fuel stands conspicuous. The 

 idea of first converting the fuel into a combustible gas, and con- 

 veying this to the point where heat was required, and there ignit- 

 ing it, is a very old one,* and, in one form or another, it has been 

 employed for over a thousand years ; but it is only within the pres- 

 ent century that the manifold advantages of gas as a metallurgi- 

 cal fuel have become fully recognized by the iron and steel work- 

 ers of the world. The early gas furnaces used in Silesia, Sweden, 

 and other European countries were but enlarged modifications of 

 Geber's Tower of Athanor, and, although they were a great im- 

 provement on the furnaces in which solid fuel was burned on a 

 grate, yet they were not able to produce a temperature suffi- 

 ciently high and controllable to satisfy the demands of the rapidly 

 developing iron and steel industries. 



The gas furnace most commonly used in the American iron 

 and steel works was invented about thirty years ago by the broth- 

 ers Frederick and Charles William Siemens, German engineers 

 resident in London. The first " Siemens furnace " built in this 

 country under the sanction of these inventors was erected at the 

 works of John A. Griswold & Co., at Troy, N. Y., in 1867, and 

 was used as a " heating furnace." f This was followed in the 



* The first gas furnace of which we have any exact account was invented by Abu 

 Musa Dschabir, more commonly known as Geber, an Arabian alchemist, who lived in the 

 eighth century. The furnace invented by Geber he called the Tower of Athanor, or the 

 undying one, because from its construction a steady and uniform heat could be maintained 

 for an indefinite period. 



t Previous to this, however, in 1862, there had been erected, at the copper-works of 

 Park, McCurdy & Co., in Pittsburgh, a " Siemens furnace " for refining copper ; and in 

 1864 Park Brothers & Co. (also of Pittsburgh) built one of these furnaces for heating steel ; 

 and in the same year, in a neighboring establishment (James B. Lyon & Co.) one was con- 



