The idea, looked at from a distance and in the abstract, seemed feasible enough; but when they came to face the physical difficulties, it was found to be hard of realisation. There was the danger of getting the explosives into the place, the danger of detection, and, finally, the chance of an accident hoisting the engineer with his own petard, especially at that time of the year when nitro-glycerine was notoriously dangerous on account of the crystals which cold formed upon its surface, and the least jar or shake was sufficient to cause an explosion. Obviously, the plan was a cumbrous one, and without hesitation it was abandoned. But the main idea, that of getting rid of the claimants at one blow, was not abandoned; it grew and grew, and occupied their minds day and night. At last the thought of transferring the Guy Fawkes expedient from the land to the ocean, which, once the deed was successfully accomplished, would tell no tale, occurred to them. The claimants must come over on shipboard, if only they could be got into one or even two ships; and if these vessels sank upon the voyage suddenly without a warning! This was certainly much safer for the conspirators, as no trace would be left, and it was surer of success, because in the hall some of the victims might escape—at sea they could scarcely do so. They ran over in their minds the various methods of scuttling ships which have been invented from time to time. There was the good old simple plan of boring holes in the bottom with augurs. There was the devilish coal-shell. A box painted to resemble coal, but really containing powder, was thrown among the coal, and when placed in the furnace blew up the boiler, and destroyed the ship. There was the ship-rat—a contrivance by which the very motion of the vessel caused an augur in a box to bore its way through, and so cause a leak. Some benevolent socialists, anxious for the welfare of man, had also promulgated a notion of exploding nitro-glycerine by clockwork, arranged to go so long, and set to act just as the vessel was farthest from land. But all these seemed to Marese and Theodore clumsy, risky, and, what was worse, uncertain of operation. It was reserved for Marese to suggest the deadliest of all destructive engines, and he arrived at its conception in this way. He had, as it were, a double mind. He was liable to flashes of inspiration—such as it was—to sudden ideas which shot through him without endeavour. He had also the power of concentrating his thoughts, and bringing the regular forms of logic to his assistance. But this latter method he could only practise with the aid of pen and ink; and it was his constant habit, whenever contemplating an important step, such as a coup upon the Exchange, to write out his plans in a regular sequence, just as he wished them to take place.