ck, almost ultra-violet-proof
atmosphere of Jupiter. Their rays were weak. And the magnetic fields of
the Mirans were unaffected. Only their atomic bombs were hindered by the
heavier gravity that pulled the rocks back in place faster than the
bombs could throw them out. Still--a few hours of work, and the IP
stations on Jupiter had rolled wildly across the flat plains of the
planet like dented cans, to end in utter destruction.

The Mirans had paid no attention to the fleeing passenger and freighter
ships that left the planet, loaded to the utmost with human cargo, and
absolutely no freight. The IP fleet had to go to their rescue with
oxygen tanks to take care of the extra humans, but nearly three-quarters
of the population of Jupiter, a newly established population, and hence
a readily mobile one, was saved. The others, the Mirans did not bother
with particularly except when they happened to be near where the Mirans
wanted to work. Then they were instantly destroyed by atomic bombing, or
gamma rays.

The Mirans settled almost at once, and began their work of finding on
Jupiter the badly needed atomic fuels. Machines were set up, and work
begun, Mirans laboring under the gravity of the heavy planet. Then,
fifty ships swam up again, reloaded with fuel, and with crews consisting
solely of uninjured warriors, and started for Mars.

Mars was half way between her near conjunction and her maximum
elongation with respect to Jupiter at that time. The Mirans knew their
business though, for they started in on the IP station on Phobos. They
were practiced by this time, and this IP station had only seven
five-foot beams. In half an hour that station fell, and its sister
station on Deimos followed. Three wounded ships returned to Jupiter, and
ten new ships came out. The attack on Mars itself was started.

Mars was a different proposition. There were thirty-two IP stations
here, one of them nearly as powerful as the Lunar Bank station. It was
equipped with four of the huge fifteen-foot beams. And it had fifteen
tons of mercury, more than seven-eighths charged. The Mars Center
Station was located a short ten miles from the Mars Center City, and
under the immediate orders of the IP heads, Mars Center City had been
vacated.

For two days the Mirans hung off Mars, solidifying their positions on
Phobos and Deimos. Then, with sixty-two ships, they attacked. They had
made some very astute observations, and they started on the smaller