An inspection was made, and those on board of the submarine craft soon learned the nature of the defensive method the Russian naval officers had adopted.
"That's pretty good," mused Oscar.
"I'm afraid its going to beat us!" declared Andy. "No telling what may happen if we run into those wires."
"They may contain current enough to shock the Holland and kill everybody on board," said George Dross.
The matter was talked over for a quarter of an hour.
In the meantime the other warships had drawn up in line and all were preparing to bombard the city beyond, which contained so much of gold and silver.
"Well, we've got to do something," said Oscar. "I have an idea."
His idea was nothing less than to float a torpedo out of the Holland XI. and attach it to a long line, setting the time fuse at ten minutes.
They would then tow the torpedo into such a position that the drift of the ocean would pull it under the Ivan II.
The job was a delicate and dangerous one, for the fuse when once set, might become entangled in the line and set the torpedo off prematurely.