This was considered an adequate defence against the nippers of a Syndicate crab; but as a means of offence against these almost submerged vessels a novel contrivance had been adopted. From a great boom projecting over the stern, a large ship's cannon was suspended perpendicularly, muzzle downward. This gun could be swung around to the deck, hoisted into a horizontal position, loaded with a heavy charge, a wooden plug keeping the load in position when the gun hung perpendicularly. If the crab should come under the stern, this cannon could be fired directly downward upon her back, and it was not believed that any vessel of the kind could stand many such tremendous shocks. It was not known exactly how ventilation was supplied to the submarine vessels of the Syndicate, nor how the occupants were enabled to make the necessary observations during action. When under way the crabs sailed somewhat elevated above the water, but when engaged with an enemy only a small portion of their covering armour could be seen. It was surmised that under and between some of the scales of this armour there was some arrangement of thick glasses, through which the necessary observation could be made; and it was believed that, even if the heavy perpendicular shots did not crush in the roof of a crab, these glasses would be shattered by concussion. Although this might appear a matter of slight importance, it was thought among naval officers it would necessitate the withdrawal of a crab from action. In consequence of the idea that the crabs were vulnerable between their overlapping plates, some of the Adamant's boats were fitted out with Gatling and machine guns, by which a shower of balls might be sent under the scales, through the glasses, and into the body of the crab. In addition to their guns, these boats would be supplied with other means of attack upon the crab. Of course it would be impossible to destroy these submerged enemies by means of dynamite or torpedoes; for with two vessels in close proximity, the explosion of a torpedo would be as dangerous to the hull of one as to the other. The British Admiralty would not allow even the Adamant to explode torpedoes or dynamite under her own stern. With regard to a repeller, or spring-armoured vessel, the Adamant would rely upon her exceptionally powerful armament, and upon her great weight and speed. She was fitted with twin screws and engines of the highest power, and it was believed that she would be able to overhaul, ram, and crush the largest vessel armoured or unarmoured which the Syndicate would be able to bring against her. Some of her guns were of immense calibre, firing shot weighing nearly two thousand pounds, and requiring half a ton of powder for each charge. Besides these she carried an unusually large number of large cannon and two dynamite guns. She was so heavily plated and armoured as to be proof against any known artillery in the world.