Seen through the glasses, disregarding ordinary roads and traveled routes, the tanks' slatey backs seemed like prehistoric turtles whose natural habitat is shell-mauled earth. They were the last word in the business of modern war, symbolic of its satire and the old strife between projectile and armor, offensive and defensive. If two tanks were to meet in a duel, would they try to ram each other after ineffectually rapping each other with their machine guns?
"I hope that it knows where it is going!" exclaimed a brigadier-general, as he watched one approach his dugout across an abandoned trench, leaning over a little as it dipped into the edge of a shell-crater some fifteen feet in diameter with its sureness of footing on a rainy day when a pedestrian slipped at every step.
There was no indication of any guiding human intelligence, let alone human hand, directing it; and, so far as one could tell, it might have mistaken the general's underground quarters for a storage station where it could assuage its thirst for gasoline or a blacksmith's shop where it could have a bent steel claw straightened. When, finally, it stopped at his threshold, the general expressed his relief that it had not tried to come down the steps. A door like that of a battleship turret opened, and out of the cramped interior where space for crew and machinery is so nicely calculated came the skipper, who saluted and reported that his ship awaited orders for the next cruise.
Soon the sight of tanks became part of the routine of existence, and interest in watching an advance centered on the infantry which they supported in a charge; for only by its action could you judge whether or not machine gun fire had developed and, later, whether or not the tanks were silencing it. The human element was still supreme, its movement and its losses in life the criterion of success and failure, with an eternal thrill that no machine can arouse. If the tanks had accomplished nothing more than they did in the two great September attacks they would have been well worth while. I think that they saved twenty-five thousand casualties, which would have been the additional cost of gaining the ground won by unassisted infantry action. When machines manned by a few men can take the place of many battalions in this fashion they exemplify the essential principle of doing the enemy a maximum of damage with a minimum to your own forces.