63. New Cotton Gin.—This gin has, instead of saws, a card cylinder 8 or 9 inches in diameter, covered with coarse wire teeth, with considerably more bend or hook than the ordinary card tooth. The cylinder revolves against a spirally-fluted cast-iron roller, the tooth being about 1⁄10 inch, and the space between the teeth 3⁄10 inch broad.
To save the expense of turning and fluting the roller, it is cast in lengths of about 6 inches, which are bored and turned at the ends, and then put together, the tooth and space being left as they are cast.
In contact with the card cylinder, a cylindrical brush, 28 inches diameter, is made to revolve. The card cylinder makes 200 revolutions, the fluted stripper 400 in a contrary direction, and the cylindrical brush 800 revolutions per minute.
When the raw cotton is introduced with its seeds between the card cylinder and the stripper (which are placed just so far apart as to stop the seeds from passing), the hooked teeth of the card take hold of the fibres and pull them from the seed, which is held up against the roller as long as any fibres cling to it for the card teeth to hold by: the seeds are then released, and fall to the ground. The spirally-fluted roller causes
