gements; 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
calculated, which means that any given locality is so many degrees east
or west of it. Sandy Hook is in longitude 74 deg., or it is that number of
degrees west of Greenwich. Aden is in 45 deg. east longitude."

"Then you find how many miles it is by multiplying the number of degrees
by 69," suggested Miss Blanche.

"You have forgotten about knots, or sea-miles," said Louis.

"So I have! I should have said multiply by 60," added the young lady.

"That would not do it any better," replied Scott.

"Degrees of latitude are always the same for all practical purposes; but
degrees of longitude are as--

'Variable as the shade
By the light quivering aspen made,'"

continued the third officer, who was about to say "as a woman's mind;"
but he concluded that it was not quite respectful to the lovely being
before him.

"What a poetical sea-monster you are, Mr. Scott!" exclaimed Miss Blanche
with a silvery laugh.

"I won't do so any more," Scott protested, and then continued his
explanation. "Degrees of longitude vary from nothing at the poles, up to
69.07 statute, or 60 geographical or sea-miles, at the equator. We are
now in about 15 deg. north latitude; and a degree of longitude is 66.65
statute miles, or 57.9855 sea-miles, near enough to call it 58. By the
way, Louis, multiply the number of statute miles by .87, and it gives
you the sea-miles. Divide the knots by the same decimal, and it gives
the statute miles."

"I w