One of these, carefully worked on both faces, and with one edge sharpened by grinding, was found at Strachur,[1529] Argyllshire, and is shown full size in Fig. 252. Another, 2 1∕2 inches long and 7∕8 inch broad, with less grinding on the surface, was found at Cromar, Aberdeenshire. A third, of almost the same size, with the edge nearly straight and the back curved, and with neatly chipped faces but little ground, was found in a chambered cairn at Camster,[1530] Caithness. A nodule of iron ore was found with it, but whether this was for fire-producing purposes is not apparent. A fragment of another knife of the same kind was found, in 1865, by Messrs. Anderson and Shearer in a cairn at Ormiegill Ulbster, Caithness; and among the numerous articles of flint found at Urquhart,[1531] Elgin, is a very perfect knife of this kind, which is shown in Fig. 253. All five specimens are in the National Museum at |339| Edinburgh. I have two English specimens of the same kind but pointed at the butt, from the neighbourhood of Icklingham. The sharpened ends of stone celts, when broken off, have occasionally been converted into knives. One such, from Gilling, Yorkshire, with the fractured surface rounded by grinding, is in the Greenwell Collection. Another form of knife closely allied to the type of Fig. 251, is broader, and has all its edges sharpened. The instrument shown in Fig. 254 was found near Bridlington. It is made from a large broad flake, the outer face of which has been re-worked to such an extent that not more than one-fourth of the original surface remains intact. The inner face, on the contrary, is left almost untouched, except just at the two ends. As will be seen from the engraving, a portion of the original edge has been chipped away, apparently in modern times, by the first finder having used it as a “strike-a-light” flint. What remains of the original edge has been carefully sharpened, and the angles between some of the facets on the convex face have also been removed by grinding. An example of the same kind from Butterlaw,[1532] near Coldstream, has been figured. [Illustration: Fig. 254.—Bridlington. 1∕2] [Illustration: Fig. 255.—Overton. 1∕2] Others more or less perfect have been found at Glenluce,[1533] Earlston, and on the Culbin Sands.[1534] A nearly similar instrument, from Sweden, has been engraved by Nilsson,[1535] but its edges are not described as ground.