Where and how is a beginning to be made? The useful and necessary thing is to visualise the fact that varied hints on bridge-building accompanied the descent of man, so the influence of their utility was active through all the linked growth in that organic chain by which the earliest men and their nearest allies were united. Sooner or later the mere use of natural bridges would generate in some minds a desire to copy them; and although we are quite ignorant as to when this desire came for the first time out of the darkness, yet we may suppose, without any great extravagance, that it belonged to the same period of handicraft as the earliest manufactured tools and weapons, which were a development from stone clubs and spears fashioned into shape by earthquakes and volcanoes, the first armourers of the Stone Age. As soon as a tribe, guided by a savage of genius, began to copy three or four object-lessons in Nature’s perennial school for mimics, the imitation of several others would be suggested by the same trend of thought, sooner or later. It is reasonable to believe that hand-made weapons preceded hand-made bridges, as hunting and fighting were the strongest motive-powers behind human needs and actions. To slay was the herald of to build, so the first bridges of handicraft ought to be placed in a likely inference among the later doings of Palæolithic hunters and warriors. A horrible slowness marked each advance from a bad copy of a natural bridge to a slightly better one. In fact, only a few brilliant creative minds--not more than two or three thousand--separate our own social order from the strife of Palæolithic savages. Into the coarse dough of humanity an infrequent genius has put some enchanted yeast. And we must needs believe that the dead routine of imitation, to which human nature has ever been enslaved, held primeval man even more relentlessly than it holds ourselves. One misfortune more than any other delayed a creeping progress: it was the fact that mankind had no cause to fear the most intelligent creatures among the lesser organisms. If snakes and beasts of prey had been as clever as were bees and ants and beavers, men could have saved themselves from extermination by one means only--by a rapid advance from frequent good ideas into great achievements. Day after day the large human brain would have been called upon to produce large protective thoughts, and, had it failed to produce them day after day, the human race would have been food for enterprising rivals. We have no guess why Providence withheld from mankind this high discipline, this fateful choice between death and a swift intelligence; but we do know that the most dangerous of the lesser organisms have been the least quick-witted, and that men in their intercourse with natural things have shown a lethargic mimicry. Their cave-dwellings were stolen from cave-lions and cave-bears; their pit-dwellings were copied from the holes and tunnels burrowed by many