“What do you mean by saying you do not know the run?” demanded Louis.

“I do know the run; but that was not what you asked me,” answered Scott with the same mischievous smile.

“What did I ask you?”

“The first time you asked me all right, and I should have answered you if I had not felt obliged to switch off and inform you and Miss Woolridge of my new appointment.  The second time you put it you changed the question.”

“I changed it?” queried Louis.

“You remember that when Mrs. Blossom asked Flix where under the sun he had been, he replied that he had not been anywhere, as it happened to be in the evening, when the sun was not overhead.”

“A quibble!” exclaimed Louis, laughing.

“Granted; but one which was intended to test your information in regard to a nautical problem.  You asked me the second time for the run of to-day for the last twenty-four hours.”

“And that was what I asked you the first time,” answered Louis.

“I beg your pardon, but you asked me simply for the run to-day.”

“Isn’t that the same thing?”

“Will you please to tell me how many hours there are in a sea-day?” asked Scott, becoming more serious.

“That depends,” answered Louis, laughing.  “You have me on the run.”

“You will find that the bulletin signed by the first officer gives the run as 330 miles; but the answer to your second question is 337 miles, about,” added the third officer.  “Just here the day is only twenty-three hours and forty minutes long as we are running; and the faster we go the shorter the day,” continued the speaker, who was ciphering all the time on a card.

“I don’t see how that can be,” interposed Miss Blanche, with one of her prettiest smiles.

“There is the lunch-bell; but I shall be very happy to explain the matter more fully later in the day, Miss Woolridge, unless you prefer that Louis should do it,” suggested Scott.

“I doubt if I could do it, and I should be glad to listen to the explanation,” replied Louis, as they descended to the main cabin; for the new third officer was permitted to retain his place at the table as well as his state-room.

The commander had suggested that there was likely to be some change of cabin arrangements; for it was not in accordance with his ideas of right that the third officer should be admitted to the table, while the first and second were excluded; and Louis was very desirous that his friend Scott should remain in the cabin.  The repasts on board the steamer were social occasions, and the party often sat quite an hour at the table, as at the present luncheon.  But as soon as the company left their places, Louis and Miss Blanche followed the third officer to the promenade deck, to hear the desired explanation of sea-time.

“Of course you know how the longitude of the ship is obtained, Miss Woolridge?” the young officer began.