being provided on its under side with a number of angular corrugations, so that it is somewhat suggestive of the jaw and teeth of an alligator. The "ball" from the puddling-furnace was placed between the upper and lower jaws of this squeezer, and the workmen turned it with tongs at each upward movement of the upper jaw (always moving it toward the fulcrum of the lever), thus causing the ball to be forcibly squeezed by each downward movement; and when the operation was completed the most of the liquid cinder had been expelled from the ball, which had assumed the form of a bloom.
Although this apparatus was of sufficient capacity for shingling a very much larger product than the trip-hammer which it displaced, yet it required the assistance of a workman, or "shingler," as he was called; and, as the number of puddling-furnaces increased in the mills, it soon became evident that more rapid and purely automatic machinery for shingling puddle-balls was desirable. This want was supplied by the inventive genius of Henry 
Fig. 27.—The Rotary Squeezer. Burden, of Troy, N. Y., who in 1840 invented the "rotary squeezer." Fig. 27 is an elevation of the original form of this machine, and Fig. 28 is a horizontal section of Fig. 27 on line A B. The construction consisted substantially of a heavy cast-iron casing or "scroll," a a (Fig. 28), firmly attached to four surrounding columns, which stood upon a heavy bed-plate and also sustained a massive casting which formed the upper support and bearing of a vertical shaft to which the heavy cast-iron drum b (Fig. 28) was firmly attached; below the bed-plate is seen (in Fig. 27) the gearing for giving motion to the shaft and drum.
The "puddle-ball" was thrown into the machine at the place indicated by the arrow (Fig. 28), and, as the drum b revolved rap-
