It is almost universally conceded that to-day, as in the past, fortifications play the most important rule in the. defense of coasts and harbors. In the United States, submarine mines and other obstructions are officially regarded as auxiliaries...
The rational use of coast-artillery, and the development of a correct system of defence, are based upon a knowledge of the means of defence, of the capability of those means, and of the method of employing them.