the variations in the relative thickness of the instruments, I have engraved, in Fig. 206, a small specimen from the Yorkshire Wolds.
Fig. 206.—Yorkshire.
When the chipping to an edge is continued beyond a semicircle, in the case of scrapers made from broad short flakes, an almost circular instrument is the result. These discoidal scrapers are of extremely common occurrence on the Yorkshire Wolds. Fig. 207 shows a specimen from Helperthorpe.
Fig. 207—Helperthorpe.
They are not unfrequently formed from external flakes or splinters, and are sometimes made from fragments broken from long flakes, inasmuch as there is no bulb of percussion on the flat face. In rare cases the flat face is the result of a natural fracture, and, more rarely still, it is the external face of a flint nodule.
When the instrument is broader than it is long, it has been termed a side scraper. One in what is now white flint, made from a portion of a flake, and showing no bulb on the flat face, is engraved in Fig. 208. It was found at Weaverthorpe. Occasionally the arc is flatter and longer in proportion to the height than in this instance.
Fig. 208.—Weaverthorpe.
