One reason for this trial run was to prove that she could run so many miles an hour under water by the power of her storage-batteries alone. And soon she went at that. And no mild racket inside her then; for a sub's engine power and space are out of all proportion to her tonnage. Not to decrease the noise, the man to whom the trial meant most was standing by with a stop-watch, and every half-minute or so he would yell at the top of his lungs, "Go!" or "Hold!" to the engineer, who was imprisoned in a narrow alleyway with engines to right and to left and below him. The engineer would look at a register and yell back at the manager, who would then set some figures in a book and rush over to the man who was reckoning up the decreasing or increasing amperes or kilowatts or whatever they were of her storage-batteries, and set down more figures; and if the boss had to yell his head off to make himself heard, be sure that the others had to yell even louder. Only on trial trips, probably, where tests have to be proved, does all this yelling happen; but the total effect was to make a shore-goer feel, not as if he were in a ship under water, but rather in a subway section under construction, or some overdriven corner of some sort of night-working machine-shop, or some other homelike place ashore. The bright electric lights helped out the machine-shop illusion. For a time during the run the diving-rudder man had his troubles keeping her on a level, whereupon the skipper--an easy-going man ordinarily--jerked his head away from his periscope and had a peek for the reason. Through the forward bulkhead door he spied the torpedo man, who, feeling pleased, perhaps, at the successful execution of his part of the programme, was fox-trotting fore and aft for himself in his section of the ship. "Would you mind picking out one spot and staying on it?" asked the skipper, at which the torpedo man took his camp-stool, picked out his one spot, and planted himself on it, and piously read the stock-market quotations of a week-old newspaper for the rest of the run.