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.
She was a floating fortress, with men enough to make up the population of a town, and with stores, ammunition, and coal sufficient to last for a long term of active service. Such was the mighty English battleship which had come forward to raise the siege of the Canadian port.
The officers of the Syndicate were well aware of the character of the Adamant, her armament and her defences, and had been informed by cable of her time of sailing and probable destination. They sent out Repeller No. 7, with Crabs J and K, to meet her off the Banks of Newfoundland.
This repeller was the largest and strongest vessel that the Syndicate had ready for service. In addition to the spring armour with which these vessels were supplied, this one was furnished with a second coat of armour outside the first, the elastic steel ribs of which ran longitudinally and at right angles to those of the inner set. Both coats were furnished with a great number of improved air-buffers, and the arrangement of spring armour extended five or six feet beyond the massive steel plates with which the vessel was originally armoured. She carried one motor-cannon of large size.
One of the crabs was of the ordinary pattern, but Crab K was furnished with a spring armour above the heavy plates of her roof. This had been placed upon her after the news had been received by the Syndicate that the Adamant would carry a perpendicular cannon over her stern, but there had not been time enough to fit out another crab in the same way.
When the director in charge of Repeller No. 7 first caught sight of the Adamant, and scanned through his glass the vast proportions of the mighty ship which was rapidly steaming towards the coast, he felt that a responsibility rested upon him heavier than any which had yet been borne by an officer of the Syndicate; but he did not hesitate in the duty which he had been sent to perform, and immediately ordered the two crabs to advance to meet the Adamant, and to proceed to action according to the instructions which they had previously received. His own ship was kept, in pursuance of orders, several miles distant from the British ship.