d design her and her sister-ship,
the _Sirius_, which Brandon and Westfall are using as a floating
laboratory. But times change, and the inefficient must go. She's a good
old tub, but she was built when everybody was afraid of space, and we
had to put every safety factor into her that we could think of. As a
result, she is four times as heavy as she should be, and that takes a
lot of extra power. Her skin is too thick. She has too many batteries of
accumulators, too many life-boats, too many bulkheads and air-breaks,
too many and too much of everything. She is so built that if she should
break up out in space, nobody would die if they lived through the
shock--there are so many bulkheads, air-breaks, and life-boats that
no matter how many pieces she broke up into, the survivors would find
themselves in something able to navigate. That excessive construction
is no longer necessary. Modern ships carry ten times the pay-load on
one-quarter of the power that this old battle-wagon uses. Even though
she's only four years old, she's a relic of the days when we used to
slam through on the ecliptic route, right through all the meteoric
stuff that is always there--trusting to heavy armor to ward off
anything too small for the observers and detectors to locate. Now, with
the observatories and check-stations out in space, fairly light armor
is sufficient, as we route ourselves well away from the ecliptic and so
miss all the heavy stuff. So, badly as I hate to see her go there, the
old tub is bound for the junk-yard."

* * * * *

A few more flights of stairs brought them to the upper band of dirigible
projectors, which encircled the hull outside the passengers' quarters,
some sixty feet below the prow. They were heavy, search-light-like
affairs mounted upon massive universal bearings, free to turn in any
direction, and each having its converter nestling inside its prodigious
field of force. Stevens explained that these projectors were used in
turning the vessel and in dodging meteorites when necessary, and they
went on through another almost invisible door into a hall and took an
elevator down to the main corridor.

"Well, you've seen it, Miss Newton," Stevens said regretfully, as he
led her toward the captain's office. "The lower half is full of heavy
stuff--accumulators, machinery, driving projectors, and such junk, so
that the center of gravity is below the center of action of the driving
projecto