"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.

"Papa explained it to me once, but I could not understand it," replied the
fair maiden.

"Then we will explain that first. One of the great circles extending
through the poles is called the prime meridian; and any one may be
selected, though that of Greenwich has been almost universally adopted.
This place is near London. From this prime meridian longitude is