he emptiness of space as your _caroj_ pass
over the desert. Your people have forgotten about that and lost the
science and knowledge you once had, but in other worlds the knowledge
is still held."

"Madness!"

"Not at all, it is science, though many times confused as being the
same thing. I'll prove my point. You know that I could never have been
inside your mysterious building out there, and I imagine you can be
sure no one has told me its secrets. Yet I'll bet you that I can
describe fairly accurately what is in there--not from seeing the
machinery, but from knowing what must be done to oil in order to get
the products you need. Do you want to hear?"

"Proceed," Edipon said, sitting on a corner of the table and balancing
the knife loosely in his palm.

"I don't know what you call it, the device, but in the trade it is a
pot still used for fractional distillation. Your crude oil runs into a
tank of some kind, and you pipe it from there to a retort, some big
vessel that you can seal airtight. Once it is closed you light a fire
under the thing and try to get all the oil to an even temperature. A
gas rises from the oil and you take it off through a pipe and run it
through a condenser, probably more pipe with water running over it.
Then you put a bucket under the open end of the pipe and out of it
drips the juice that you burn in your _caroj_ to make them move."

Edipon's eyes opened wider and wider while Jason talked until they
stuck out of his head like boiled eggs. "Demon!" he screeched and
tottered towards Jason with the knife extended. "You couldn't have
seen, not through stone walls, yet only my family have seen, no
others--I'll swear to that!"

"Keep cool, Edipon, I told you that we have been doing this stuff for
years in my country." He balanced on one foot, ready for a kick at the
knife in case the old man's nerves did not settle down. "I'm not out
to steal your secrets, in fact they are pretty small potatoes where I
come from since every farmer has a still for cooking up his own mash
and saving on taxes. I'll bet I can even put in some improvements for
you, sight unseen. How do you monitor the temperature on your cooking
brew? Do you have thermometers?"

"What are thermometers?" Edipon asked, forgetting the knife for the
moment, drawn on by the joys of a technical discussion.

"That's what I thought. I can see where your bootleg joyjuice is going
to take a big jump in quality, if you have anyone here wh