Arrow-heads have been found in such quantities, and of such variety, that we can here only give a general outline of their classification. It has been estimated that about ten thousand exist in collections at the present time, not including those which have been sent out of the country, which probably amount to as many more. In size arrow-heads measure from about 1 inch to 4; these latter, indeed, and those up to about 7 or 8 inches long, must have been used as javelin or spear-points; but, as there is no hard-and-fast dividing line between them, all may be included in a general description. Some have been found under one inch in length, but these are not common. The spear-head (fig. 2) in the National Museum is 6½ inches long and nearly 2 inches broad at the widest part. It was rubbed smooth after chipping, and is, perhaps, the most perfect of the class yet found. Owing to their great variety of form, it is difficult to make a classification of arrow-heads simple enough to cover all. For general purposes, however, a three-fold division will suffice: leaf-shaped, triangular, and stemmed. An examination, however, of any good collection will show that further sub-division is needed under each head, if a thorough classification and arrangement are required. The _Leaf-shaped_ arrows are very varied in shape and size; and to this class belong some of the largest, many of them showing the most perfect manipulation and delicacy of touch in regard to the chipping. As the name indicates, these are in general shaped like a leaf; but this class also includes a large variety of those of a modified leaf-form. They were the easiest to make, and were probably the earliest in point of time. [Illustration: Leaf-shaped Arrow-heads.] [Illustration: Triangular Arrow-heads--first type.] [Illustration: Triangular Arrow-heads--second type.] [Illustration: Various types of Stemmed Arrow-heads.] _Triangular_ arrow-heads are very numerous, and much more so in Ireland than in England. Most of the objects of this class have an inward curve in the base, or are notched, leaving barbs or wings between which the split-shaft was placed. The _Stemmed_ arrow-heads were probably a development from the leaf or triangular types, and their advantage over them is obvious. The head was kept in its place and prevented from splitting the shaft, while the barbs rendered the weapons more effective in war or in the chase. These vary with long or short stems: some are without barbs; others have barbs and stems of equal length; while varieties may be noticed in the edges being straight, curved either concave or convex, some having a combined or slightly S-shaped curve. [Illustration: Mounted Arrow-head.]