"The torpedo, carrying a one-hundred-pound charge, can be projected in a straight line to a distance of eighty or ninety feet, according to the power employed in expelling it. The method of attack will probably be as follows: The diving boat, with only her turret above water, moves toward the ship. When she gets so close that her presence may be discovered, say half a mile, she descends a few feet under the surface. Once or twice, after the bearing of the ship is observed by means of a telescope projected for a few minutes over the water, corrections are made in the course for deviations owing to currents. "When near the vessel she goes deeper, so as to bring her stem ten or fifteen feet beneath the surface. Netting can thus be avoided. She can now discharge her torpedo, to explode on contact. As soon as this strikes, the explosion occurs and a large hole is torn in the ship's side. The ship will now become unmanageable, and with assistance may be captured. Experience has shown that in a seaway she rolls or pitches very little, apparently following the wave slope in large waves. In short, sharp ones, she seems to rise and fall bodily with very little tendency to pitching. "A notion seems to prevail that the proper duty of a diving boat would be to carry a diver, who could come out and fasten a torpedo to a ship at anchor, then retire into his boat and move away; also, that it would be useful in placing and removing stationary mines. It is very evident that if a diving boat can attain a speed of ten or twelve miles per hour, fire torpedoes at ships moving at full speed, and keep to sea for days together, her sphere of usefulness would be greatly extended. In fact, there is no insuperable objection to the employment of such vessels for coast defence and operations against ships. Submarine mines are not so effective against them as vessels on the surface, because they can pass them unobserved. They can enter a harbor that may be thoroughly defended, should it be necessary to destroy vessels inside the defences. If those on the fleet become aware of their presence it is more than probable, judging from the action of the French fleet in 1877-78, that the moral effect of the discovery will be that they will feel convinced of the foolishness of awaiting an attack when the time so employed may be more wisely expended in moving to a safe distance, and in getting there at full speed. Thus, in 1886, did I try to show by comparison the superiority of the submarine over the torpedo boats and gunboats, the two arms of defence on which the Navy placed all its confidence at the time."