The Dolphin sped on down the river current to the sea. Thus far Frank had kept the boat on the surface.
When the open sea was reached he said:
“I think that for the first thousand miles of our course we will travel faster under water. I have studied the ocean bed, and there are no obstructions to encounter at the proper mean elevation.”
“Then we are to start out at once with a thousand mile voyage under water?” asked the explorer Stanhope.
“Yes.”
“Good! I am very glad of that. There is much in the Atlantic worthy of study. You will make the Pacific by way of Cape Horn?”
To Stanhope’s surprise Frank shook his head.
“No,” he said. “That is the longest route.”
“What other is there?”
“By the Northwest Passage.”