"I cannot account for it," said the captain. "Possibly the commander has some little human sympathy left, and does not want to drown us like rats in a cage." Neither the captain nor the boys slept much that night. They were too much occupied with constantly watching the manoeuvers necessary on the part of the commander and his crew to prevent detection as they passed up the Channel. "I have spent years on the Channel as a navigating officer and in charge of various types of ships in the merchant service, as well as on our own naval vessels, and I know, probably, better than the lieutenant in charge of the submarine, what the dangers are. It is my belief that the lieutenant has come over this course before, and probably knows a safe, or measurably safe route, and has taken the chances of returning, but no one, however skilful a navigator he may be, can be sure of making exactly the same course twice. The tides may be against him; he may be out of his reckonings hundreds of feet, and that is too big a margin, where a hundred feet in width is the limit through which his vessel may pass in safety." The captain thus, in general terms, set forth the perils of the route that the commander of the submarine had taken, and stated also, very plainly, that they must now be prepared to meet the greatest of all dangers. Sleep, therefore, could not be considered. The long and weary night at last came to an end, and the appetizing odors of the morning meal were wafted to them. Their toilets were exceedingly simple affairs, a small cake of soap, warm water, and a long towel serving for the three. They had no trouble in dressing, for their clothing had not been removed. They were obliged to dispense with the bath, for, although all these boats are provided with comforts of that kind, none of them was available to the captain and the boys, and they did not ask that any privileges be extended to them. No sooner had breakfast been served than the machinery began to slow down until finally it ceased. Not a perceptible motion was now observed. A pulsator or two were at work, and a slight rumble due to the action of the dynamo came to their ears. "I suppose we are now on the bottom," suggested Ralph. "Yes; during the daytime it will be necessary to keep quiet. Even the periscope may reveal our presence," remarked the captain. A little information as to the activities of the crew during these periods of rest may be interesting. Idleness breeds discontent and mischief. It is upon the principle that constant work encourages contentment and makes for efficiency, that the Germans require the continued activity which was shown by the occupants of the submarine.