various European articles penetrate into the heart of Africa.
This kind of traffic is proved to have extended over enormous distances in the Neolithic age, by the distribution of the axes made of nephrite or jade, a material as yet unknown in its native state in Britain or on the Continent. The only places where it is known to exist in the old world are Turkestan and China, where from time immemorial it has furnished supplies to the Chinese and Tartars. It is very probable that jade was worked in this district in the Neolithic age, and transported through Asia, by the steady westerly drifting of the tribes; passing from hand to hand, and in the course of many ages arriving in Britain. Its value consisted not merely in its rarity, hardness, and beautiful green colour, but in the superstitious virtues attached to it in all ages and among all peoples; equally among the Chinese and the New Zealanders at the present time, and the ancient inhabitants of Europe. In the Neolithic age the axes made of it were put to no common use, but were frequently suspended as charms or ornaments, and this was the case also in the succeeding Bronze age.
Navigation.
The intercourse between the Neolithic tribes was greatly facilitated by the use of canoes, formed of the trunk of large trees, hollowed partly by the action of fire and partly by the use of the axe, and propelled by means of a broad paddle. There is no evidence of sails having been then known. It was probably in canoes of this kind, some of which are forty feet long, that the Neolithic peoples with their cattle and household stuff
