part I want, but also the machine that makes the machine that
makes the machine that makes it--and so on, just how far down the line,
I haven't dared to think."

"You must be a regular jack-of-all-trades, to think you can get away
with such a program as that?"

"I am--nothing else but. You see, while most of my school training
was in advanced physics and mathematics, I worked my way through by
computing and designing, and I've done a lot of truck-horse labor of
various kinds besides. I can calculate and design almost anything, and
I can make a pretty good stab at translating a design into fabricated
material. I wouldn't wonder if Brandon's ultra-radio would stop me,
since nobody had even started to build one when I saw him last--but I
helped compute it, know the forces involved as well as he did at that
time, and it so happens that I know more about the design of coils and
fields of force than I do about anything else. So I may be able to work
it out eventually. It isn't going to be not knowing how that will hold
me up--it'll be the lack of something that I can't build."

"And that's where you will go back and back and back, as you said about
building the penstock?"

"Back and back is right, if I can find all the necessary raw
materials--that's what's probably going to put a lot of monkey-wrenches
into the machinery." And Stevens went to work upon a weapon of offense,
fashioning a crude, but powerful bow from a strip of spring steel strung
with heavy wire.

"How about arrows? Shall I go see if I can hit a bird with a rock, for
feathers, and see if I can find something to make arrows out of?"

"Not yet--anyway, I'd bet on the birds! I'm going to use pieces of this
light brace-rod off the accumulator cells for arrows. They won't fly
true, of course, but with their mass I can give them enough projectile
force to kill any small animal they hit, no matter how they hit it."

After many misses, he finally bagged a small animal, something like
a rabbit and something like a kangaroo, and a couple of round-bodied,
plump birds, almost as large as domestic hens. These they dressed,
with considerable distaste and a noticeable lack of skill.

"We'll get used to it pretty quick, Diana--also more expert," he said
when the task was done. "We now have raw material for bow-strings and
clothes, as well as food."

"The word 'raw' being heavily accented," Nadia declared, with a grimace.
"But how do we know that they're good to eat