The same sort of ridge occurs on pounding-stones from Denmark, Portugal,[957] Spain,[958] Ireland, and elsewhere, and occasionally extends all round the stone when it happens to be disc-shaped, like those already mentioned from Upton Lovel and elsewhere. Hammer-stones worn to a ridge are also found in Egypt.[959] It would appear that the face of the hammer was ground away, either by a rocking motion on a flat stone, or by the blows given with it being administered alternately from the right and from the left, so as to keep any matter that was being pounded with it from being driven out of position. |248| I have, lastly, to notice the more or less polished condition of one of the faces of these stones, which may be due to their being used for grinding the material already pounded by their edges to a finer powder on the slab, which served instead of a mortar. One of the flat pebbles found in the Cave of La Madelaine, Dordogne, appears to have served as a muller for grinding the hæmatite used as paint. Sometimes these hammer-stones are mere pebbles without any previous preparation, and indeed it is but natural that such should have been the case. Canon Greenwell has found pebbles of quartz and greenstone, worn and battered at the ends, accompanying interments on the Yorkshire Wolds, and such are also occasionally present on the surface, though they are, of course, liable to escape observation. A quartzite pebble that has served as a hammer-stone, and is much worn and fractured by use, was found at Ty Mawr, and is figured in the _Archæological Journal_,[960] as are also several from hut-circles in Holyhead and Anglesea.[961] A large sarsen-stone pebble, weighing 4 3∕4 lbs., and which had obviously been used as a hammer, was found in the Long Barrow, at West Kennet,[962] Wiltshire. A large conical sort of muller of sarsen-stone,[963] weighing 12 1∕2 lbs., was discovered with twenty-two skeletons, various animal remains, and pottery, in a large cist, in a barrow near Avebury. Mr. G. Clinch has a hammer from West Wickham, made from a nearly cylindrical quartz pebble, much worn at both ends, one of which is more rounded than the other. [Illustration: Figs. 167 and 168.—Yorkshire Wolds. 1∕2]