er--and poison gas.
I must prepare our arms."

"Would our heat-ray actually set them afire, Steve?" Nadia asked, as the
plate went blank.

"I'll say it would. I'll show you what heat means to them--showing
you will be plainer than any amount of explanation," and he shot the
visiray beam down toward the city of Titania. Into a low-lying building
it went, and Nadia saw a Titanian foundry in full operation. Men clad
in asbestos armor were charging, tending, and tapping great electric
furnaces and crucibles; shrinking back and turning their armored heads
away as the hissing, smoking melt crackled into the molds from their
long-handled ladles. Nadia studied the foundry for a moment, interested,
but unimpressed.

"Of course it's hot there--foundries always _are_ hot," she argued.

"Yes, but you haven't got the idea yet." Stevens turned again to the
controls, following the sphere toward what was evidently a line of
battle. "That stuff that they are melting and casting and that is so
hot, is not metal, but _ice!_ Remember that the vital fluid of all life
here, animal and vegetable, corresponding to our water, is probably
more inflammable than gasoline. If they can't work on ice-water without
wearing suits of five-ply asbestos, what would a real heat-ray do to
them? It'd be about like our taking a dive into the sun!"

"_Ice_!" she exclaimed. "Oh of course--but you couldn't really believe
a thing like that without seeing it, could you? Oh, Steve--how utterly
horrible!"

* * * * *

The "Barkodar" had dropped down into a line of sister ships, and had
gone into action in midair against a veritable swarm of foes. Winged
centipedes they were--centipedes fully six feet long, hurling themselves
along the ground and through the air in furious hordes. From the flying
globes emanated pale beams of force, at the touch of which the Sedlor
disappeared in puffs of vapor. Upon the ground huge tractors and trucks,
manned by masked soldiery, mounted mighty reflectors projecting the same
lethal beam. From globes and tanks there sounded a drumming roar and
small capsules broke in thousands among the foe; emitting a red cloud of
gas in which the centipedes shriveled and died. But for each one that
was destroyed two came up from holes in the ground and the battle-line
fell back toward Titania, back toward a long line of derrick-like
structures which were sinking force-rods into the ground in furious
haste.

S