Perhaps the greatest element of care which man has had to devote to the horse is found in the matter of shoeing. In the state of nature the admirably constructed hoof sufficiently provided the animal against the excessive wearing of its horny extremity. Nature, however, rarely provides for more strength and endurance than the creature in its wild state demands; and so it comes about that when horses have to bear burdens or draw carriages, particularly on roadways, their unprotected feet will not withstand the strain which is put upon them, the rate of growth of the structure composing the hoof not being sufficiently rapid to make good the wearing which these unnatural conditions impose. For thousands of years, in the roadless stages of man's development, the difficulties arising from the wearing of the hoof were not serious, for the creatures trod either on turf-covered plains or on the soft ways of the desert. When the advance of culture made roads necessary, when carriages were invented and something like our modern conditions were instituted, it became imperatively necessary to provide additional protection for the feet. We find the Greeks, in the classic time, wrestling with this problem. Xenophon, in his treatise on the care of horses, advises that they be reared on stony ground, he having observed that, in a natural way, the hoof becomes somewhat adapted to the necessities of its conditions. The Romans found the difficulty from the tender foot of the horse yet more serious on their paved roads; but both these classic people showed, in their ways of dealing with the difficulty, that lack of inventive skill which so curiously separates the olden from the modern men. They devised soles of leather and bags as coverings for the horse's feet, but none of the contrivances could have been very serviceable. All such coverings must have been quickly worn out in active use. So far as we can determine, it was not until about the fourth century of our era that the iron horseshoe was invented. This valuable contrivance appears to have originated in Greek or Roman lands, probably in the former realm, for it first bore the name of "selene," from its likeness to the crescent shape of the new moon. Although simple, the horseshoe was a most important invention, for it completely reconciled the animal to the conditions of our higher civilization by removing the one hinderance to its general use in the work of war and commerce. It is probable that with this invention began the great task of differentiating the several breeds of European horses for their use in various employments, as draught animals for packing purposes, as light saddle horses, and the bearing of armored men. Neither the draught nor the war horses of Europe could well have been specialized until their heavy bodies were separated from the ground by these metallic coverings of the hoof. [Illustration: Syrian Horse]