It is indeed remarkable that the proximity of raw material, except in cases when this is very bulky, as with ores, seems often to be of minor importance in localising industries. Thus, though Belfast may be said to owe its linen industry primarily to local supplies of flax, it is noticeable that the local supply is very limited, and several towns on the east coast of Scotland, as Dunfermline, Montrose, Arbroath, etc., have a flourishing linen industry maintained entirely by imported raw material. A whole host of facts of this kind emphasise the importance of power in the case of a modern industry, as contrasted with the supreme importance of abundant raw material in the old days when man himself chiefly supplied the motive force. In other words, modern industry has been very closely associated with improved means of communication, which alone make it possible to carry cheap raw material over great distances, without excessive expense for freight. The study of the development of the means of communication is therefore a problem well worth the attention of the geographer, and is one which has many interesting facts to disclose. Man himself is an animal relatively ill-adapted for continuous rapid movement or for the transport of goods. As a transport animal he is the costliest and most inefficient known, and were it not for the intelligence which enabled him first to utilise other animals for his own purposes, and later to find mechanical means, the progress of civilisation would have been impossible. Progress in Africa has been greatly checked by the fact that over a large area man is the only transport animal available, a fact which brings in its train the slave trade, and many other serious evils. Except in certain special localities the surface of the earth is so uneven that progression, especially for a loaded man or animal, is very difficult except on a prepared surface. On the other hand, the diminution of friction over a water surface makes transport over it relatively easy. It has been pointed out that, as a result of this fact, the great civilisations have developed in regions where water transport was possible, and have involved the progressive utilisation of larger and larger masses of water. The first civilisations developed in river valleys, where water transport in one direction at least is very easy. The next stage was that which saw man settled on the shores of the great inland sea, and witnessed his gradual acquisition of greater and greater skill in navigation. As we have seen, he was soon not content with that sea alone, but launched out into the open, and, hugging the coastline, found his way to far Britain.