CHAPTER XII

THE DISCOVERY FROM THE CONNING TOWER

“Go up slanting, or on an even keel?” called up Mr. Farnum.

“On the even keel,” came the answer.

“All right, then; we’ll know soon.”

For this purpose the largest compressed air container of all was to be employed.  It distributed great volumes of compressed air to all the water tanks, forcing open the valves and driving out the water.

“Any of you youngsters know where the proper wrench is?” inquired the builder, looking keenly at the boys.

There was an instant start, followed by widespread pallor.

“Oh, it’s not right to keep you in torment,” laughed the builder.  “I have kept the wrench in my pocket, all along.”

He drew it out, holding it up before their gaze.  Though technically a wrench, it looked more like a very large key.  It was of curious construction, intended to supply the greatest amount of force with the least amount of exertion.

“Watch me,” commanded Jacob Farnum.  “Any one of you may have to use this wrench at any time.”

Little did any of them guess the tragedy that was destined to center around that life-saving wrench later on.  Now, with the boys gathered about him, Mr. Farnum fitted the wrench with great care and deliberation.

“See how easily it’s intended to turn?” asked the builder, giving it a slight turn.

All three of the boys nodded.

“Now, we’ll give it more,” continued Mr. Farnum.  He swung the wrench well around in order to release compressed air with a rush and great force into the water tanks.

Then he stood there, waiting.  There was no perceptible motion or other change that the boys could note about the boat.

“Wha—­what makes it act so slowly?” asked Eph Somers, in a queer voice.  “Or isn’t it going to act?”

For some seconds more the four stood there looking at one another.  Andrews came to the doorway of the engine room, looking anxious.

“We’ve released a lot of compressed air,” uttered Mr. Farnum.  “More than half of the force in the receiver is gone.”

A few seconds more passed.  Then restless Eph sprang to the stairway.

“Mr. Pollard,” he cried, nervously, “when on earth—­under the sea, I mean—­are we going up?  What’s wrong?”

“Going up?” called down the inventor.  “This isn’t an airship.”

“When are we going to strike the surface?” Eph insisted.

“Why, we’re awash already.  Don’t you notice I’ve just shut off the electric motor?”

That was true, although none of the quartette had yet realized that the propeller shafts were stilled.

“Awash, are we?” cried Eph, in an incredulous voice.

“If you can’t believe it,” replied David Pollard, calmly, “come up and see for yourself.”  Eph accepted that invitation with such alacrity that he tripped and barked his shins against one of the iron steps, but recovered and darted up in no time.