air."

"Don't bother yourself about that, Sarah," said Sammy. "We'll have all
the air we want; of course we would not start without thinkin' of that."

"I don't know," said Sarah. "It's very seldom that men start off
anywhere without forgettin' somethin'."

"Let us take our seats, Mrs. Block," said Mr. Gibbs, "and I will set
your mind at rest on the air point. There are a great many machines
and mechanical arrangements on board here which of course you don't
understand, but which I shall take great pleasure in explaining to you
whenever you want to learn something about them. Among them are two
great metal contrivances, outside the Dipsey and near her bows, which
open into the water, and also communicate with the inside of her hull.
These are called electric gills, and they separate air from the water
around us in a manner somewhat resembling the way in which a fish's
gills act. They continually send in air enough to supply us not only
with all we need for breathing, but with enough to raise us to the
surface of the water whenever we choose to produce it in sufficient
quantities."

"I am glad to hear it," said Mrs. Block, "and I hope the machines will
never get out of order. But I should think that sort of air, made fresh
from the water, would be very damp. It's very different from the air we
are used to, which is warmed by the sun and properly aired."

"Aired air seems funny to me," remarked Sammy.

There was fascination, not at all surprising, about the great glass
lights in the Dipsey, and whenever a man was off duty he was pretty sure
to be at one of these windows if he could get there. At first Mrs. Block
was afraid to look out of any of them. It made her blood creep, she
said, to stare out into all that solemn water. For the first two days,
when she could get no one to talk to her, she passed most of her time
sitting in the cabin, holding in one of her hands a dustbrush, and in
the other a farmer's almanac. She did not use the brush, nor did she
read the almanac, but they reminded her of home and the world which was
real.

But when she did make up her mind to look out of the windows, she became
greatly interested, especially at the bow, where she could gaze out
into the water illuminated by the long lane of light thrown out by
the search-light. Here she continually imagined she saw things, and
sometimes greatly startled the men on lookout by her exclamations. Once
she thought she saw a floating corpse, bu