With this idea in view torpedo boars, destroyers designed to attack torpedo boats and submarines have been multiplied in modern navies. We have just begun to appreciate the effectiveness of this type of vessels. Their possibilities are enormous and their latent power renders the bombardment from sea of town or fort a far more perilous operation than of old. Fired at by the great guns of the fort capable of effective work at eight or ten miles distance, exposed to explosive bombs dropped from soaring airships, made a target for the deadly weapon of the torpedo boat, and in constant risk of being stung by the submarine wasp, these great war ships, built at a cost of ten or more millions and peopled by hundreds of mariners, are in constant danger of being sent to the bottom with all on board a contingency likely to shake the nerves of the steadiest Jack Tar or admiral on board. A typical submarine has a length of about 150 feet and diameter of 15 feet, with a speed of eleven knots on the surface and five knots when submerged. Some of the more recent have a radius of navigation of 4,500 miles without need of a new supply of stores and fuel. On the surface they are propelled by gasoline engines, but when submerged they use electric motors driven by storage batteries. If the weather should grow too rough they can sink below the waves. THE NEW TYPE OF BATTLESHIP While the peril of the big ship has thus been increased, the size and fighting capacity of those ships have steadily grown and at the same time their cost, which is becoming almost prohibitive. Taking the British navy, the leader in this field, the size of battleships was yearly augmented until in 1907 the famous Dreadnought appeared, looked upon at the time as the last word in naval architecture. This great ship was of 17,900 tons displacement and 23,000 horse-power, its armor belt eleven inches thick, its major armament composed of ten twelve-inch guns. There are now twenty British battleships of larger size, some much larger. On shore a similar increase may be seen in the size and effectiveness of armies and the strength of fortifications. In all the larger nations of Europe except Great Britain the whole able-bodied male population are now obliged to spend several years in the army, and to be ready at a moment’s notice to drop all the avocations of peace and march to the front, ready to risk their lives in their country’s service or at the command of the autocrat under whom they live. MOBILIZATION