Harper's New Monthly Magazine, Volume 2, No. 12, May, 1851.
[Illustration: THE BENDING AND PUNCHING ENGINES.]
The plates, when cut, are to be bent to the proper curvature. The machine by which this bending is effected is seen above, in the back-ground. It consists of three rollers, placed in such a position in relation to each other, that the plate, in being forced through between them, is bent to any required curvature. These rollers are made to revolve by great wheels at the sides, with handles at the circumference of them, which handles act as levers, and are worked by men, as seen in the engraving.
The separate plates