* * * * * These, of oval section, form the third subdivision of polished celts, which I now proceed to describe. * * * * * It will be observed that implements of this character, formed of flint, are extremely rare. The reason for this appears to be, that from the method in which, in this country, flint celts were chipped out, the sides were in all cases originally sharp, and they had a pointed oval, or _vesica piscis_, section. In polishing, this form was to a great extent preserved, though the edges were, as has been seen, sometimes ground flat and sometimes rounded. It rarely happens, however, that the rounding is carried to so great an extent as to produce such a contour that it is impossible to say within a little where the faces end and the sides begin; though this is often the case with celts of greenstone and other materials, which were shaped out in a somewhat different manner, and in the formation of which grinding played a more important part. It is almost needless to say that I use the word oval in its popular sense, and not as significant of a mathematically true ellipse. At the part where the edge of the celts commences, the section is of course a _vesica piscis_. The first specimen engraved, Fig. 67, is in my own collection, and was found in the Thames at London. It is of dark greenstone, and, owing to a defect in the piece of stone of which it was made, there is a hollow place in one of the faces. General Pitt Rivers has a similar but more symmetrical celt, of the same material, also found in the Thames. Another, smaller, from the same source, is in the British |123| Museum; and another (8 inches) from the collection of the late Rev. T. Hugo, F.S.A.,[401] is now mine. Its edge is rather oblique. I have another from the Thames (7 1∕2 inches) with a symmetrical edge. [Illustration: Fig. 67.—Thames, London. 1∕2] Large implements of this form are of not uncommon occurrence in Scotland and in the Shetland Isles. There are several in the National Museum at Edinburgh, and also in the British Museum, and in that of Newcastle. The butt-end is occasionally pointed, and the faces in broad specimens, flatter than in Fig. 67. Several of these celts |124| in the British Museum were found in the middle of the last century, in Shetland. The largest is 11 inches long, 3 inches wide at the edge, and 1 3∕4 inches thick. It was found in Selter,[402] parish of Walls. Others are from 8 inches to 9 inches long. In the case of one, 12 inches long, from Shetland, and in the Edinburgh Museum, the edge is oblique. [Illustration: Fig. 68.—Near Bridlington. 1∕2]