To obviate the spring of tools which must, of necessity, be held out a long way from the tool-post, the ful-crum off which the tool springs must be adjusted so as not to stand in advance of the cutting edge of the tool. In the engraving, a represents the fulcrum off which the tool takes its spring; B is the work to be cut; and the dotted line, C, is the line in which the point of the tool would spring (being in the direction denoted by the arrow), which is not in this case into' the cut, but rather away from it, in consequence of the point of the tool standing back from a line perpendicular to the line of the back part of the tool, as shown by the dotted line, D.

Spring-Tool