o can do some
simple glassblowing. Though it might be easier to rig up a coiled
bi-metallic strip. You're trying to boil off your various fractions,
and unless you keep an even and controlled temperature you are going
to have a mixed brew. The thing you want for your engines are the most
volatile fractions, the liquids that boil off first like gasoline and
benzene. After that you raise the temperature and collect kerosene for
your lamps and so forth right on down the line until you have a nice
mass of tar left to pave your roads with. How does that sound to you?"

* * * * *

Edipon had forced himself into calmness, though a jumping muscle in
his cheek betrayed his inner tension. "What you have described is the
truth, though you were wrong on some small things. But I am not
interested in your thermometer nor in improving our water-of-power, it
has been good enough for my family for generations and it is good
enough for me...."

"I bet you think that line is original?"

"... There is something that you might be able to do that would bring
you rich rewards. We can be generous when needs be. You have seen our
_caroj_ and ridden on one, and seen me go into the shrine to intercede
with the sacred powers to make us move. Can you tell me what power
moves the _caroj_?"

"I hope this is the final exam, Edipon, because you are stretching my
powers of extrapolation. Stripping away all the _shrines_ and _sacred
powers_ I would say that you go into the engine room to do a piece of
work with very little praying involved. There could be a number of
ways of moving those barns, but let's think of the simplest. This is
top of the head now, so no penalties if I miss any of the fine points.

"Internal combustion is out, I doubt if you have the technology to
handle it, plus the fact there was a lot to do about the water tank
and it took you almost an hour to get under way. That sounds like you
were getting up a head of steam--the safety valve! I forgot about
that. So it is steam. You go in, lock the door of course, then open a
couple of valves until the fuel drips into the firebox, then you light
it. Maybe you have a pressure gauge, or maybe you just wait until the
safety valve pops to tell you if you have a head of steam. Which can
be dangerous since a sticking valve could blow the whole works right
over the mountain.

"Once you have the steam you crack a valve to let it into the
cylinders and get the