The backward motion of the diving craft ceased. She began to creep forward.
All at once, Mr. Ironsides pressed a button at his elbow. A sharp click responded, and the water in front of the Huron became illuminated with a flood of brilliant, blinding white light. Tom could see fish dart off out of the lane of light like coveys of partridges. Some, fascinated seemingly by the rays, flocked about the conning tower, dashing themselves against its thick lenses like moths round a lamp chimney.
"That searchlight is the most powerful I could devise," said Mr. Ironsides, in a tone of quiet satisfaction. "I guess it's doing its work all right."
"I guess so," agreed Tom enthusiastically. The boy had quite forgotten his alarm in the sensation of watching the wonderful illumination of the waters.
"Keep a sharp lookout," urged the inventor. "I am anxious to see what it was that we struck."
Tom found himself wondering over the necessity for this, but he held his peace, and busied himself in gazing out of the conning tower windows. For some time nothing appeared in the field of light but masses of water. The liquid looked greenish and almost solid—like thick glass—in the powerful rays of the searchlight.
"It must be somewhere hereabout," commented Mr. Ironsides, after several minutes had gone by without revealing anything.
He began to move the searchlight about, controlling its shiftings by a worm-gear and wheel.
All at once Tom spied something, a dark, indefinite-looking mass, off to the right.
"Look! Look there, Mr. Ironsides!" he cried.