He could see nothing, for the fog was as impenetrable as a blanket He began to swim toward the sound.

He could not tell whether the whistle was that of the tug or the _Merry Seas_ or of some other vessel.

Again he sent up a call for help.

The water was cold and his clothing heavy.

He was thinking of trying to get out of his shoes and outer coat, when he heard a human cry not far away.
"Help! help!" some one called.
"Help! help!" Frank shouted.
But instead of swimming on, he turned in the direction of the cry.