calculated, which means that any given locality is so many degrees east
or west of it. Sandy Hook is in longitude 74°, or it is that number of
degrees west of Greenwich. Aden is in 45° 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° north latitude; and a degree of longitude is 66.65