But the war lasted only nineteen months longer; and in that time the Americans were not able to do anything like what the Allies had done before and still were doing. The entire American loss in men (killed, wounded, and prisoners) was over one-quarter million. But Canada's loss of over two hundred thousand was ten times as great in proportion; for there are twelve-and-a-half times as many people in the United States as there are in Canada. In the same way the losses of France and Great Britain were each more than twenty times greater than that of the United States. In ships and money the difference is far more striking still. The British alone lost one-and-a-half times as many ships as all the rest of the world put together. But the Americans have actually gained, owing to the number of interned German vessels they seized in their ports. As for money: the British, the French, and all the Allies have spent so much in fighting for the freedom of the world that neither they nor their children, nor their children's children, can ever pay the vast debt off; while the United States have made, on their own showing, the twelve-and-a-half "billions" mentioned already. These few facts (there are hundreds more) will show you a little of what the Great War means to the world, what the British Navy meant to the war, and what Jutland meant to both the war and the world, by sweeping the German Navy off the surface of the sea, and so bringing on the "Submarine Blockade" that itself forced the American Government to fight in self-defence. [Illustration: British Submarine.] The Germans, wishing to kill off their victims one at a time, were ready for the French and Russian Navies, but not for the British. They had less than forty sea-going submarines when the war began. But nearly four hundred took part, or were ready to take part, before the war was over, while many more were building. We have already noted the weak points of submarines. They are "tender" because they must be thin. An old collier that couldn't steam faster than you could walk sank a submarine by barging into it, end-on--one can hardly call it ramming. Submarines are slower on the surface than dreadnoughts, cruisers, and destroyers; and, after doing a total of ten or twelve hours under water, they have to recharge their batteries; for they run by oil engines on the surface and by electricity submerged, and the crew would be smothered if the oil engines tried to charge batteries without coming up.