The halberd blade can be distinguished from the broad dagger by the shape of the handle, which is curved or indented in the case of the dagger, but straight across in the case of the halberd. There is, however, another point. The hindmost rivets, both in the case of the blades with four rivets and those with three only, are shorter than those in front of them. The shortness of the end-rivets and slope of the heads imply that the handle was rounded off behind the blade, as would be the case with a transverse shaft. So there appears no room to doubt the manner in which the long scythe-shaped blades were mounted on handles, though some uncertainty was formerly expressed on the subject. The Irish halberd-blades were evidently mounted at right angles to the shaft in the same way as most of the Continental blades, as can be seen from the straight-across marks of the handle, which can be traced on several examples. [Illustration: Fig. 13.--Rock Markings, Maritime Alps.] From the analyses of copper halberds, it will be seen that the tin varies from .18 to .31 per cent. We may therefore conclude that the copper halberds are simply coarse or unrefined copper from similar ores to the copper celts; and that the copper implements found in Ireland may contain up to about .5 per cent. of tin. An increasing percentage of tin was not found in any of the copper celts, or, contrary to expectation, in the copper halberds; but, judging from the widespread use of copper implements in Ireland, from which it may be inferred that copper remained in use for a considerable time, it seems probable that bronze was introduced as an alloy of a known percentage of tin. As relatively few analyses of Irish bronze implements have been made, it is not possible at present to come to any fixed conclusions on the subject of the introduction of bronze into Ireland. [Illustration: Fig. 14.--Stone Pick from the Bann.] [Illustration: Fig. 15.--Deer Horn Pick.]