AMERICAN INDUSTRIES SINCE COLUMBUS. 589 



placed between them. The "gate" g, to which the upper knife is 

 attached, has a vertical reciprocating motion communicated to it 

 by means of the eccentrics e and the rods /, and, as the upper 

 knife h has an inclined edge, the shearing will commence on the 

 right and gradually extend to the left as the " gate " g descends. 

 Shears of this description have been made to cut ten feet in length 

 at one movement of the " gate " g. Such tools are very heavily 

 geared, and are usually driven by a special steam-engine. 



The first iron-works in the United States in which iron was 

 puddled and rolled into bars was built by Colonel Isaac Meason, 

 in 1816 and 1817, at Plumsock, on Redstone Creek, between Con- 

 nellsville and Brownsville, in Fayette County, Pennsylvania. 

 Swank tells us that " Thomas C. Lewis was the chief engineer in 

 the erection of the mill, and George Lewis, his brother, was the 

 turner and roller. They were Welshmen." 



We have no exact description of the machinery of this mill, 

 but we are told that, in addition to the rolls, " the mill contained 

 two puddling-furnaces, one refinery, one heating furnace, and one 

 tilt-hammer " ; and that " the iron was refined by blast and then 

 puddled." This mill produced " bars of all sizes, and hoops for 

 cutting into nails." The mill was started on September 15, 1817, 



Fig. 45. Train of Eolls for Square and Flat Bar Iron (1817). 



and continued in operation until 1824, when it was destroyed by 

 a flood, and never rebuilt. Although we have no details of the 

 roll train used in this mill, it is fair to assume that, as its design- 

 ers were Welshmen, they followed as closely as possible the prac- 

 tice with which they were familiar. Fig. 45 is an elevation of a 

 train of rolls such as was in common use in England and Wales 

 at the beginning of this century for rolling square and flat bar 



