Knowledge that Transforms

Machines for planing stone have been used for many years. The original machines were simply iron-planers slightly reconstructed, and were worked by a gear-and-rack drive. They were successful in planing flaggings and other paving material for which a smooth surface was not required, but could not be used on building material. About i88o a new type of planer was designed, in which a screw was substituted for the gear-and-rack drive. A regular motion was thus attained, and the machine became a practicable means of working building stone. It was possible, not only to plane stone on the machine, but also by the use of various forms of edges to cut moldings of any ordinary design. A large part of this work had formerly been done by skilled stonecutters using chisel and hammer. The planer, however, by no means entirely replaced the stonecutter. It was still necessary to employ stonecutters to do much that the machine could not do. Also, it was cheaper to do small pieces by hand than to mount them on the planer.