"Good-morning, Mrs. Belgrave; good-morning, Louis; I hope you have both slept well," said the captain, saluting them.
"I have slept like a rock all night long," replied the lady.
"I have fallen into sailors' ways, so that I go to sleep whenever I lie down," added Louis. "I could sleep my four hours on board of the Maud, and wake at the right time without being called. But where are we now, sir?"
"You see the lighthouse ahead; that is in latitude 25°. We are now nearly as far south as the first cataract on the Nile, as far south as we went in Africa."
"I can understand that better than simple figures," said Mrs. Belgrave.
"But we went a little farther south than that off Cuba," suggested Louis.
"We shall cross the Tropic of Cancer while we are at luncheon," added the commander. "You learned at school that this boundary was at twenty-three and a half degrees north of the equator, and it is generally so stated, though it is not quite accurate."
"I wish you would explain this at the next conference, Captain Ringgold, for what you say is a surprise to me," said Louis.
"I will do it in a general way, though I am not an astronomer in the scientific sense of the word," answered the captain. "We are approaching the Dædalus lightship. I suppose you remember the name."
"I know that Dædalus was a very ingenious artist of Athens, who planned the Cretan labyrinth, invented carpentry and some of the tools used in the trade; but I don't know why his name was given to this lighthouse."