turned on the radial rods to hold the said rollers in exact position on same. Turned bosses must be provided on both the inner and the outer ends of the rollers, to bear against the collars and the friction-washers.

An inner spacing-ring, of size commensurate with the magnitude of the drum, is to be attached to the radial rods. For large drums this should be in the form of a small curved plate girder lying in a horizontal plane and rigidly braced to the centre casting by radial struts that are riveted at the outer ends to the curved girder and at the inner ends to a large circular plate which fits snugly around a turned bearing on the centre casting. With this detail the radial rods are to be dispensed with, and in their stead are to be substituted heavy square bars, having their outer ends detailed as described for the radial rods, and their inner ends attached to the circular girder so as to hold the bars in a position exactly radial to the drum. These bars should not be less than two and a half (2 1/2) inches square, and the journals should not be less than three (3) inches in diameter. There must be nuts at both ends of the bars so as to move the rollers in a radial direction, and the inner ends of the bars are to be so attached to the circular plate as to permit of the correction of any slight variation of their axes from a truly radial direction.

The centre casting must be made strong and heavy, and must be effectively anchored to the top of pier by eight (8) or more anchor-bolts not less than one and one-fourth (1/4) inches in diameter and not less than three (3) feet long. These bolts are to be made of soft steel, with cold-pressed threads and hexagonal nuts at top, and with split ends and wedges at bottom. The least allowable thickness of metal for this casting shall be one and one-half (1 1/2) inches. The base shall be true and level; and an even bearing shall be secured by bedding in neat, Portland-cement mortar. For heavy draws this centre casting is to be set well into the masonry, then grouted in place.

All bearings for plates which rotate on this casting are to be turned smooth, and are to be provided with suitable oil-grooves, so they can be easily oiled.