Although the horse was known to the Indo-European family before its separation, it was probably not applied to domestic uses at that early date. Riding, indeed, was so late an accomplishment to its members that it was unfamiliar to the poets of the Rig Veda or the Homeric songs. The heroes of the Trojan war are not cavalrymen, but go forth to the con test in chariots of war.
Leading authorities now are of opinion that at least eight varieties of the wild horse were domesticated, two in Asia and six in Europe (Pietre ment). One of the Asiatic breeds was introduced into Egypt by the Shepherd Kings (about 2200 B. c.), and from this all the African horses descended. They were soon highly prized, especially for the increased efficiency they gave the armies. Plutarch relates that the god Horns was once asked by his father Osiris, "Which is the most useful of ani mals?" His reply was, " The horse, because it enables a man to over take and slay his enemy." Both chariots and horsemen are frequently represented on Egyptian monuments later than the middle dynasties.
II7zerled I and very early inventions, were familiar to the Assyrians, Semites, and early Greeks. The native Britons encountered Julius Cxsar in their esseda, two-wheeled war-chariots drawn by fiery steeds. This proves that the application of the mechanical principle of the wheel had at that time become the property of many nations, and with this arose the necessity of bridges and of roads much broader, more level, and kept in better condition than the trail which would suffice for the pedestrian or equestrian.
The first wheels were a mere narrow section of the trunk of a tree, the axle turning with them ; and it is one of several curious examples of reversion that the most modern invention for car-wheels, both in plan and material, goes back to this antique pattern, for it joins wheel to axle, and the wheel is of " paper pulp," principally consisting of wood-fibre.
It is needless to specify in how many directions the requirements of transportation have developed the industrial arts as well as the abstract sciences. They have demanded the excavation of canals and docks, and the construction of quays, harbors, roads, and bridges. They have been the practical purposes which have originated the sciences of geography and astronomy, and they have led nations to unite in friendly legislation for the furtherance of common interests and for banishing banditti from the highways and pirates from the ocean.
/Th-ia/ water and the land thus brought under peaceful subjection to man, the mountains perforated with his tunnels, and the seas united by his artificial water-ways, the air alone has resisted his repeated endeavors to render it the medium of his motions. From the day that Daedalus fastened wings to his son Icarus and bade him fly across the Cretan Sea, into which he fell and was drowned, inventor after inventor has spent his life on the problem of aerial navigation with no greater success, and often with like unhappy result. The daily spectacle of the flying birds, however, proves that the problem is no unsolvable one, and we may confidently look to the time foretold by the poet when the "pilots of the purple twilight" shall "drop down with costly bales."