If we had one hundred submarines distributed over our Atlantic and Pacific coast lines, it would take weeks or months to mobilize many of them at the point of attack, for the reason that a submarine, when submerged, has such a small radius of action. The best in the service to-day have a radius of action of about one hundred miles at five knots, or eleven miles at ten and one-half knots, or twenty-four miles at eight knots. The enemy, with light, shallow-draft, high-speed picket boats, could probably make it very unsafe for a submarine to travel any considerable distance along the coast in the daytime, or even at night, in surface cruising condition. As it takes considerable time to charge the batteries to enable the boat to run in a submerged condition, should the enemy have control of the surface of the sea, the average submerged radius to-day of a submarine would probably be less than one hundred miles, unless it ran a grave risk of being captured while on the surface. The chances are, therefore, that if we had one hundred submarines distributed over our Atlantic and Pacific coast lines, not over ten or a dozen of them would be able to reach the point of attack in time to prevent the landing of an invading force with sufficient men, guns, and ammunition to do a great deal of harm in some of the thickly populated sections of the country. [Illustration: AN AMPHIBIOUS SUBMARINE BEING HAULED OUT OF THE WATER] If, however, the country were provided with fifty "amphibious submarines" located at ten of our important Atlantic and Pacific ports, they could all be mobilized at an objective point within a week. If the government made arrangements with the railroads to run a track down under the water at each railroad coast terminal, or to run special tracks into the water at other suitable localities along the coast where there would be sufficient water to float a submarine, submarines could be rapidly mobilized to ward off a landing at any point. To illustrate the point which I wish to make, assume that this country should become involved in war with nations lying both to the east and west of us. To get submarines from one coast to the other would require a long period of time. The "amphibious submarine," on the contrary, could in an hour's notice be run on to the tracks at New York and three days later be run into the water at San Francisco, with her crew, fuel, stores, and torpedoes all ready to go into action at once. A submarine could make a trip from Boston to New York in five hours, or from Boston to New Orleans in thirty-five hours. These boats could be built in quantities at a cost of about $300,000 (£61,500) each. Fifty of them could, therefore, be built at approximately the cost of one modern battleship.