With a small fleet of these under-water fighting vessels—say of two or three—an invading or blockading fleet of not more than twenty men-of-war can be destroyed within an hour by an otherwise unprotected harbor or port.

Germany has a few of these latest style submarines, and if it can rush the construction of the thirty-one now being built, it will have a flotilla that will protect its harbor towns against invasion.

France, also with its fifty submarines and thirty-one under construction, and its great corps of scouting aeroplanes, will prove a formidable agent in crippling the activities of Germany's big fleet of dreadnoughts, armored cruisers and battleships. Russia will need its twenty-five submarines for coast defense and probably will not send them out of the Baltic [or out of the Black Sea in the event that Italy is drawn into the conflict.]

Undoubtedly, then, the great battles in the present war, on the water at least, may be decided by these silently moving, dinky sized, almost imperceptible submarines which carry the ever-destroying torpedoes. And the loss of lives will be more prodigious than ever.

SUBMARINE STRENGTH OF THE POWERS

Built
Great Britain....................... 69
France.............................. 50
Russia.............................. 25
Germany............................. 24
Italy............................... 18
Austria............................. 6

SUBMERGED MINES—HOW THEY ARE LAID AND THEIR WORKING

The sinking of the light cruiser Pathfinder of the British navy by a German mine in the North Sea early in the war called special attention to the deadly character of the mines of the present day.

A modern mine-laying ship puts to sea with a row of contact mines on rails along her side, ready for dropping into the sea. The rails project over the stern. The essential parts of a special type of mine of recent design consist of (1) the mine proper, comprising the explosive charge and detonating apparatus in a spherical case; (2) a square-shaped anchor chamber, connected with the mine by a length of cable; (3) a plummet-weight used in placing the mine in position, connected with the anchor chamber by a rope. Thus the mine appears on the deck of the mine-laying ship before being lowered over the stern.

Before the mine goes over, a windlass inside the plummet-sinker is revolved by hand until the length of cable between the plummet and the anchor-chamber has been reeled off equivalent to the depth below the surface at which the explosive mine is to float.