The most common form of boring tool, to which by some writers the name of awl or drill[1442] has been given, is that shown in Fig. 227, from the Yorkshire Wolds. It is formed from a flat splinter of flint, and shows the natural crust of the stone at the broad end. At the other, each edge has been chipped away from the flat face, so as to reduce it by a rapid curve on each side to a somewhat tapering blade, with a sharp point. The section of this portion of the blade is almost of the form of half a hexagon when divided by a line joining opposite angles. A borer of this kind makes a very true hole, as whether turned round continuously or alternately in each direction, it acts as a half-round broach or rimer, enlarging the mouth of the hole all the time it is being deepened by the drilling of the point. The broad base of the flake serves as a handle by which to turn the tool. Several boring instruments of this form were found in the pits at Grime’s Graves,[1443] already so often mentioned. A borer of this kind has been experimentally[1444] tried and found efficient for drilling a hole in jet. [Illustration: Fig. 228. Bridlington. 1∕1] Borers of the same character occur in Ireland[1445] and in Scotland,[1446] where natural crystals[1447] of quartz seem also occasionally to have been used as drills. I have also seen several found near Pontlevoy, France, in the collection of the Abbé Bourgeois. Similar boring instruments of flint have been found in Denmark, in company with scrapers and other tools. Two of them have been engraved by Mr. C. F. Herbst.[1448] They are common in some parts of North America, and finely chipped tools of the kind occur in Patagonia.[1449] They are also found in Natal[1450] and in Japan. Sometimes the borer consists of merely a long narrow pointed flake, which has had the point trimmed to a scraping edge on either side. A specimen of the kind, found near Bridlington, is shown in Fig. 228. The point, for about a |323| sixteenth of an inch in width, has been ground to a nearly square edge, so that it acts like a drill. Such a form was probably attached to a wooden handle for use, but I doubt whether any mechanical means were used for giving it a rotary motion as a drill, and regard these borers rather as hand-tools to be used much in the same way as a broach or rimer. Some implements from the lake settlement at Meilen, regarded by Dr. Keller[1451] as awls or piercers, are perforated at one end, and appear to be ground over their whole surface.