With the Nautilus it is true that he contemplated dragging a “bomb” beneath the bottom of a ship to be attacked, and in this respect the Nautilus possessed some feature of a true submarine. The plan that he proposed for the Nautilus presented many serious difficulties depending as it did on the fixing of a spike in the bottom of the other vessel. Fulton himself apparently reached the conclusion that this suggestion was impracticable, through actual experiments or further study. The boat that he proposed for the British Government had no such attachment, but instead was designed to carry “bombs” to be deposited secretly in an enemy harbor, and there to be anchored so as to remain beneath the surface when they would come in contact with the bottoms of passing vessels, or to be released in couples held by bridles and thus to be carried by tidal currents across the cables of anchored ships when the “bombs” would be drawn beneath the vessel and explode. What Fulton called “bombs” are today known as mines. No means are shown in his plans by which these mines could be placed or released while his boat was submerged. The capability to submerge and to move beneath the surface was expected to permit the boat to work into a harbor unperceived, and there to lie in wait beneath the surface until night presented the opportunity to rise unseen, when the mines would be placed or set free. The successful experiment with the Dorothea showed that his mines could be completely effective and that, therefore, his submersible mine layer, as perhaps she can be correctly described, could have been developed into a very effective engine of war. In Fulton’s bombs, as he calls them, we are not particularly interested because he has fully described these devices in his book that he wrote on Torpedo Warfare. It is, however, in view of subsequent events exceedingly interesting to point out that Fulton foresaw the conditions that actually obtained in the recent war. On pages 71–2 of the “Descriptions” he explained how hundreds of such bombs or mines could be strewn in the channel of the Thames or along the coast and it would not be in the power of the whole British marine to prevent such practice. This is precisely what the Germans undertook to do, forcing the British, even though they had control of the open seas, to sweep the Channel by daylight, day after day, in order to remove mines that might have been planted during the night. Furthermore, Fulton pointed out that a line of such mines could be strung from Calais to Dover, rendering it “impossible for any vessel to pass without certain destruction.” When the German submarine attack on British commerce became seriously acute, the British authorities put into execution that which Fulton had suggested and strung a line of obstructions across the Channel from Dover to Calais thereby compelling the German submarines to pass around the northern coast of Scotland in order to reach the open sea.