It seems, however, very doubtful whether any such general practice prevailed. I have seen a delicate lance-head |43| 6 inches long, of triangular section, with the broad face polished and the two other faces exquisitely fluted. In this case also the faces may have been ground before fluting. This blade was found in a cavern at Sourdes, in the Landes, and was in the collection of M. Chaplain-Duparc. With regard to the process of grinding or polishing flint and other stone implements not much need be said. I may, however, refer the reader to Wilde’s Catalogue[133] of the Museum of the Royal Irish Academy, for an account of the different processes. In all cases the grindstone on which they were polished was fixed and not rotatory, and in nearly all cases the striæ running along the stone hatchets are longitudinal, thus proving that they were rubbed lengthways and not crossways on the grinding-bed. This is a criterion of some service in detecting modern forgeries. The grinding-stones met with in Denmark and Scandinavia are generally of compact sandstone or quartzite, and are usually of two forms—flat slabs, often worn hollow by use, and polygonal prisms smallest in the middle, these latter having frequently hollow facets in which gouges or the more convex-faced hatchets might be ground, and sometimes rounded ridges such as would grind the hollow part of gouges. From the coarse striation on the body of most flint hatchets, especially the large ones, it would appear that they were not ground immediately on such fine-grained stones, but that some coarse and hard grit must have been used to assist the action of the grindstone. M. Morlot[134] thought that some mechanical pressure was also used to aid in the operation, and that the hatchet to be ground was weighted in some manner, possibly by means of a lever. In grinding and polishing the hollowed faces of different forms of stone axes, it would appear that certain rubbers formed of stone were used, probably in conjunction with sand. These will be more particularly described in a subsequent page. The surface of hard rocks or of large boulders fixed in the ground was often used for the purpose of grinding stone implements. Instances will be given hereafter.