to sabotage, and, in a way, to space travel! Listen!"

Joe dropped to the ground.

"Shoot it," he said.

He was grimly alert, just the same. There were men waiting for them to
start back to the car. These saboteurs were armed, and they intended to
murder Sally and himself. Joe's jaws clamped tautly shut at the grim
ideas that came into his mind.

But Mike was beginning to speak.

"Forget about the Platform a minute," he said, standing up to
gesticulate, because he was only three and a half feet high. "Just
figure on a rocket straight to the moon. With old-style rockets they'd
a' had to have a mass ratio of a hundred and twenty to one. You'd have
to burn a hundred and twenty tons of old-style fuel to land one ton on
the moon. Now it could be done with sixty, and when the Platform's up,
that figure'll drop again! Okay! You're gonna land a man on the moon. He
weighs two hundred pounds. He uses up twenty pounds of food and drink
and oxygen a day. Give him grub and air for two months--twelve hundred
pounds. A cabin seven feet high and ten feet across. Sixteen hundred
pounds, counting insulation an' braces for strength. That makes a pay
load of a ton an' a half, and you'd have to burn a hundred an' eighty
tons of fuel--old-style--to take it to the moon, and another hundred an'
twenty for every ton the rocket ship weighed. You might get a man to the
moon with a twelve-hundred-ton rocket--maybe. That's with the old fuels.
He'd get there, an' he'd live two months, an' then he'd die for lack of
air. With the new fuels you'd need ninety tons of fuel to carry the guy
there, and sixty more for every ton the ship weighed itself. Call it six
hundred tons for the rocket to carry one man to the moon."

Sally nodded absorbedly.

"I've seen figures like that," she agreed.

"But take a guy like me!" said Mike the midget bitterly. "I weigh
forty-five pounds, not two hundred! I use four pounds of food and air a
day. A cabin for me to live in would be four feet high an' five across.
Bein' smaller, it wouldn't need so much bracing. You could do it for two
hundred pounds. Three hundred for grub and air, fifty for me. Me on the
moon supplied for two months would come to five-fifty pounds. Sixteen
tons of fuel to get me to the moon direct! To carry the weight of the
ship--it's smaller!--fifty tons maximum!"

"I--see...," said Sally, frowning.

He looked at her suspiciously, but there was no mockery in her face.

"It'd take a six-hun