CHAPTER XVIII.

Each page of the paper is locked up on a detached segment of the large cylinder, called by the compositors a "turtle," and this constitutes its bed and chase. The column-rules run parallel with the shaft of the cylinder, and are consequently straight, while the head, advertising, and dash-rules are in the form of segments of a circle. The column-rules are in the form of a wedge, with the thin part directed toward the axis of the cylinder, so as to bind the type securely, and at the same time to keep the ink from collecting between the types and the rules. They are held down to the bed by tongues projecting at intervals along their length, which slide into rebated grooves, cut crosswise in the face of the bed. The spaces in the grooves between the column-rules are accurately fitted with sliding blocks of metal even with the surface of the bed, the ends of the blocks being cut away underneath to receive a projection on the sides of the tongues of the column-rules. The form of type is locked up in the bed by means of screws at the foot and sides, by which the type is held as securely as in the ordinary manner upon a flat bed, if not even more so. The speed of the machine is limited only by the ability of the feeders to supply the sheets. Twenty-five hundred is about as many as a man can supply in an hour, and multiplying this by ten—one man being at each cylinder—we have 25,000 sheets an hour as the capacity of the press.