the chairman, "that he
did not patent it."

VI

The helicopter would never fly again, but the time unit was
intact.

Which didn't mean that it would work.

They held a powwow at their camp site. It had been, they decided,
simpler to move the camp than to remove the body of Old Buster. So
they had shifted at dawn, leaving the old mastodon still sprawled
across the helicopter.

In a day or two, they knew, the great bones would be cleanly
picked by the carrion birds, the lesser cats, the wolves and foxes
and the little skulkers.

Getting the time unit out of the helicopter had been quite a
chore, but they finally had managed and now Adams sat with it
cradled in his lap.

"The worst of it," he told them, "is that I can't test it. There's
no way to. You turn it on and it works or it doesn't work. You
can't know till you try."

"That's something we can't help," Cooper replied. "The problem,
seems to me, is how we're going to use it without the whirlybird."

"We have to figure out some way to get up in the air," said Adams.
"We don't want to take the chance of going up into the twentieth
century and arriving there about six feet underground."

"Common sense says that we should be higher here than up ahead,"
Hudson pointed out. "These hills have stood here since Jurassic
times. They probably were a good deal higher then and have
weathered down. That weathering still should be going on. So we
should be higher here than in the twentieth century--not much,
perhaps, but higher."

"Did anyone ever notice what the altimeter read?" asked Cooper.

"I don't believe I did," Adams admitted.

"It wouldn't tell you, anyhow," Hudson declared. "It would just
give our height then and now--and we were moving, remember--and
what about air pockets and relative atmosphere density and all the
rest?"

Cooper looked as discouraged as Hudson felt.

"How does this sound?" asked Adams. "We'll build a platform twelve
feet high. That certainly should be enough to clear us and yet
small enough to stay within the range of the unit's force-field."

"And what if we're two feet higher here?" Hudson pointed out.

"A fall of fourteen feet wouldn't kill a man unless he's plain
unlucky."

"It might break some bones."

"So it might break some bones. You want to stay here or take a
chance on a broken leg?"

"All right, if you put it that way. A platform, you say. A
platform out of what?"

"Timber. There's lot of it. We just go