“Exactly.”

Frank touched the lever, and the boat instantly rose to the surface. As it came up into daylight every eye scanned the sea.

Everywhere was the unbroken expanse of rolling brine. Only one object was visible, and that was a white sail far distant on the horizon.

That it was the ship Southampton was probable.

“Shall we rejoin her?” asked Stanhope.

“I think not,” replied Frank. “Nothing will be gained. Let her go her way. We may work better alone.”

So this was the last seen of the English cutter. Her sails were soon invisible.

For some while the Dolphin traveled on the surface of the sea. Then Frank decided to go down.

So the Dolphin descended once more to submarine depths.

For a whole day she kept on thus. Then, as night was coming on, the object of the quest was again seen.