s coordinating his body
to act on those instructions.

One of the radar dials told him how far he was from the rock. Another
told him his radial velocity relative to it. A third told him his
angular velocity.

"Come to a dead stop exactly one thousand meters from the surface, Mr.
Danley," St. Simon ordered.

Danley worked the controls until both his velocity meters read zero, and
the distance meter read exactly one kilometer.

"Very good, Mr. Danley. Now assume that the surface of your rock is at
nine hundred ninety-five meters. Bring your boat to a dead stop exactly
fifty centimeters from that surface."

Danley worked the controls again. He grinned with satisfaction when the
distance meter showed nine nine five point five on the nose.

Captain St. Simon sighed deeply. "Mr. Danley, do you feel a little
shaken up? Banged around a little? Do you feel as though you'd just
gotten a bone-rattling shock?"

"Uh ... no."

"You should. You slammed this boat a good two feet into the surface of
that rock before you backed out again." His voice changed tone. "Dammit,
Mr. Danley, when I say 'surface at nine nine five', I mean _surface_!"

* * * * *

Edway Tarnhorst had been dictating notes for his reports into his
recorder, and was rather tired, so when he asked Peter Danley what he
had learned, he was rather irritated when the blond man closed his blue
eyes and repeated, parrotlike:

"Due to the lack of a water-oxygen atmosphere, many minerals are found
in the asteroids which are unknown on Earth. Among the more important of
these are: Oldhamite (CaS); Daubreelite (FECr_{2}S_{4}); Schreibersite
and Rhabdite (Fe_{3}Ni_{3}P); Lawrencite (FeCl_{2}); and Taenite, an
alloy of iron containing--"

"That's not precisely the sort of thing I meant," Tarnhorst interrupted
testily.

Danley smiled. "I know. I'm sorry. That's my lesson for tomorrow."

"So I gathered. May I sit down?" There were only two chairs in the room.
Danley was occupying one, and a pile of books was occupying the other.

Danley quickly got to his feet and began putting the books on his desk.
"Certainly, Mr. Tarnhorst. Sit down."

Tarnhorst lowered himself into the newly emptied chair. "I apologize for
interrupting your studies," he said. "I realize how important they are.
But there are a few points I'd like to discuss with you."

"Certainly." Danley seated himself and looked at the older man
expectantly. "The nullifiers