The effect of the motor-bomb was fully observed with glasses from the various fortifications of the port, and from many points of the city and harbour; and those familiar with the effects of explosives were not long in making up their minds what had happened. They felt sure that a mine had been sprung beneath Fort Pilcher; and they were now equally confident that in the morning a torpedo of novel and terrible power had been exploded in the harbour. They now disbelieved in the earthquake, and treated with contempt the pretence that shots had been fired from the Syndicate's vessel. This was merely a trick of the enemy. It was not even likely that the mine or the torpedo had been operated from the ship. These were, in all probability, under the control of confederates on shore, and had been exploded at times agreed upon beforehand. All this was perfectly plain to the military authorities. But the people of the city derived no comfort from the announcement of these conclusions. For all that anybody knew the whole city might be undermined, and at any moment might ascend in a cloud of minute particles. They felt that they were in a region of hidden traitors and bombs, and in consequence of this belief thousands of citizens left their homes. That afternoon a truce-boat again went out from Repeller No. 1, and rowed to the fort, where a letter to the commandant was delivered. This, like the other, demanded no answer, and the boat returned. Later in the afternoon the two repellers, accompanied by the crabs, and leaving the steel net still anchored in its place, retired a few miles seaward, where they prepared to lay to for the night. The letter brought by the truce-boat was read by the commandant, surrounded by his officers. It stated that in twenty-four hours from time of writing it, which would be at or about four o'clock on the next afternoon, a bomb would be thrown into the garrisoned fort, under the command of the officer addressed. As this would result in the entire destruction of the fortification, the commandant was earnestly counselled to evacuate the fort before the hour specified. Ordinarily the commandant of the fort was of a calm and unexcitable temperament. During the astounding events of that day and the day before he had kept his head cool; his judgment, if not correct, was the result of sober and earnest consideration. But now he lost his temper. The unparalleled effrontery and impertinence of this demand of the American Syndicate was too much for his self-possession. He stormed in anger.