Occasionally some projecting spur at the side of the flake has been utilized to form the borer, as is the case in Fig. 229, also from the Yorkshire Wolds. In this instance, the two curved sweeps, by which the boring part of the tool is formed, have been chipped from the opposite faces of the flake, so that the cutting edges are at opposite angles of the blade, which is of rhomboidal section. This is the case with some of the Scottish specimens,[1452] which closely resemble Fig. 229. Such a tool seems best adapted for boring by being turned in the hole continuously in one direction. In some instances the projecting spur is so short that it can have produced but a very shallow cavity in the object to be bored. [Illustration: Fig. 229.—Yorkshire Wolds. 1∕1] [Illustration: Fig. 230.—Bridlington. 1∕1] The tools, of which a specimen is shown in Fig. 230, also appear to have been intended for boring. It is, however, possible that after all they may have served some other purpose. That here engraved was found near Bridlington, and is weathered white all over. It is made from a flake, and the edge of the blade on the left in the figure is formed as usual by chipping from the flat face. The other edge is more acute, and has been formed by secondary chipping on both faces. The spur to the left, which may have served as a handle for turning the tool round when in use, has originally been longer, but the end has been lost through an ancient fracture. The edges at the point of the tool are somewhat worn away by friction.