Irish copper work is seen at its best in the numerous copper halberd
blades found in Ireland. These blades, varying from nine to sixteen
inches in length, were fastened at right angles by rivets into wooden
shafts. The blades show a slight sickle-like curve and are of the
highest workmanship. Halberds somewhat similar in type have been
found in Spain, North Germany, and Scandinavia.

Between the years 2000 and 1800 B.C. the primitive metalworkers
discovered that bronze, a mixture of tin and copper, was a more
suitable metal than pure copper for the manufacture of weapons; and
the first period of the bronze age may be dated from 1800 to 1500
B.C. The bronze celts at first differed little from those made of
copper, but gradually the type developed from the plain wedge-shaped
celt to the beautiful socketed celt, which appears on the scene in
the last, or fifth, division of the bronze age (900-350 B.C.). It was
during the age of bronze that spears came into general use, as did
the sword and rapier. The early spear-heads were simply knife-shaped
bronze weapons riveted to the ends of shafts, but by degrees the
graceful socketed spear-heads of the late bronze age were developed.

Stone moulds for casting the early forms of weapons have been found,
but, as the art of metalworking became perfected, the use of sand
moulds was discovered, with the result that there are no extant
examples of moulds for casting the more developed forms of weapons.
The bronze weapons--celts, swords, and spear-heads--are often highly
decorated. In these decorations can be traced the connection between
the early Irish civilization and that of the eastern Mediterranean.
The bronze age civilization in Europe spread westward from the
eastern Mediterranean either by the southern route of Italy, Spain,
France, and thence to Ireland, or, as seems more probable, up the