With the inspection of the gun their survey of the craft practically was over, except for the exhibition by Mr. Dancer of the anchoring device and other minor details.
When they stood once more on the top of the curved deck Jack exclaimed with enthusiasm:
“You have the finest craft of its kind I have ever seen or read of, Mr. Dancer.”
But, far from seeming elated, the inventor only sighed.
“It appears all right, I know,” he said, “and it cost me almost all my fortune to build it; but there is one fatal defect in it: the diving devices do not work properly.”
The boys regarded the gray-haired scientist with astonished eyes.
“It won’t dive?” asked Jack, at length.
“No; that is, not properly. You see, I had devised a sort of double skin for it in parts, and I imagined that I could fill this with water and make the craft sink when I so desired, and then pump out the water when I wished to rise.”
“And you did not do so?” queried Jack.
“Yes, I equipped it with the tanks all right; but I found that I would have to install such large pumps that it would be impracticable to work them with the power I had; so that now, as I told you some time ago, you find me at a standstill.”