_Hammer-Stones._--A great many water-worn pebbles, of a similar character to those found in the surrounding glacial drift and river-courses, which were used as hammers, or pounders, or rubbers, were discovered in the débris all over the crannog, but more abundantly in the deeper layers of a small circular area round the hearths, corresponding to what I have on a former occasion designated the relic-bed. As typical specimens of such implements I have collected no less than nineteen. Of these, fourteen are of a somewhat elongated oval shape, and were used at one or both ends. They vary considerably in size, the major diameter of the largest measuring 6 inches, and the rest graduating downwards to about the half of this. Two are flat and circular, and show friction-markings all round; while other three show signs of having been used on their flat surfaces only. The one represented in Fig. 48, with markings on its flat sides, is divided into two portions, each of which was picked up separately, about a yard asunder, and found to fit exactly. It would thus appear that it was broken while being used on the crannog, and then pitched aside as useless. Some are slightly chipped at one end, others have small finger-like depressions, as if intended to give the user a better grip (Figs. 49, 50, and 51). [Illustration: Fig. 50.--Hammer-Stone (1/2).] [Illustration: Fig. 51.--Hammer-Stone. Edge view of the previous implement (1/2).] _Heating-Stones and Sling-Stones._--A large number of round stones, varying in size from half an inch to three inches in diameter, some having their surfaces roughened and cracked as if by fire, but others presenting no marks whatever, were met with. The former might have been used as heating-stones for boiling water in wooden vessels,--the only ones found on the crannog,--the latter as sling-stones or missiles. _Anvil._--About a foot below the surface, and a few feet to the north of the upper fireplace, a beautiful quartz pebble was found by Mr. Cochran-Patrick, which has the appearance of being used as an anvil. It is discoidal in shape, but a little more rounded on its upper surface, and measures 27 inches in circumference. It is just such an instrument as a shoemaker of the present day would gladly pick up for hammering leather (see Fig. 37). [Illustration: Fig. 52. Fig. 53. Sharpening-Stones (1/2).] _Sharpening-Stones or Whetstones._--Four or five whetstones were collected from various parts of the island, three of which are here engraved (Figs. 52, 53, and 54). They are made of a hard smooth claystone, one only being made of a fine-grained sandstone, and vary in length from 5 to 7 inches. Fig. 54 represents what is supposed to be a hone 6-1/4 inches long, and containing a smooth groove. It was found on the site of the crannog by Captain Gillon, long after the explorations had been brought to a close, and is now deposited in the National Museum (see page 126).