"Thank you very much for your exceedingly kind offer," said I, "but I couldn't think of dispossessing you of your own cabin, even for a single night.  The sofa will serve my turn admirably, especially as I had no sleep last night, and not much during the night before.  But, before I go below, I should like to hear how it comes about that the man who was second mate of this ship when she left England is now master of her.  To bring about such a state of affairs as that you must have lost both your original skipper and your chief mate."