It is not the purpose of the writer to enter into a minute description of the craft. She was provided with a gasoline engine and an electric motor. She was not very roomy, but her appointments were very handsome and costly.
There were machines for manufacturing pure air, as is common with all submarines of her class, and the apparatus for the production of electricity was modern and efficient. Every compartment could be closed against every other chamber in case of damage to the shell.
The pumps designed to expel the water taken into the hold for the purpose of bringing the craft to the bottom were powerful, so that she seemed to sink and rise as easily as does a bird on the wing. At top speed she would make about twenty miles an hour.
On a trial trip taken by Ned on the day before the visit of Captain Moore to the Black Bear clubroom, the double doors and closet which enabled one to leave or enter the boat while under water had been thoroughly tested and found to work perfectly.
The diving suits—which had been manufactured to fit Ned and Frank,
Jack and Jimmie—were also found to be in perfect condition.
On the whole, the Sea Lion and her appurtenances were in as perfect condition as science and experience could make them on the day the four boys, accompanied by a naval officer, left the train at Oakland and proceeded to the navy yard up the bay.
By the middle of the afternoon the boys were on board, receiving their final instructions from Lieutenant Scott, who had arranged for the transportation of the Sea Lion from New York and attended to all other details connected with the trip.
After a long talk regarding the perils to be encountered, Lieutenant Scott drew forth a map of peculiar appearance and laid it on the table in the chamber which was to serve as a general living room.
"I have retained possession of this map until the last moment," the officer said, "because it is most important that no eyes but those of the occupants of the Sea Lion should rest upon it. It shows where the lost vessel went down, shows the drift there, the depths, and various other details of great moment.
"The Cutaria, as you doubtless know, went down off the Taya Islands, a small group to the east of the large island of Hainan, which, in turn, is off the coast of China, being separated, if that is a good word to use in this connection, from the eastern coast by the Gulf of Tong King.