solids is to make the ships accessible to
the metals. It spreads the matter out thin. The gravitors work very
well in the hot vapor. Behind each ship is towed a gravitor. Each
gravitor is set to attract a particular metal, somewhat the way a
magnet attracts iron, again loosely comparing. A magnet, as you know,
attracts by magnetic force. The gravitors are adjusted to attract a
metal by selecting its gravitic attraction. As the gravitor ships pass
through the vapor, the gravitors behind them attract the metal they
are set for. When load size has been reached, they are taken to the
cache near the station."

* * * * *

We watched the operation for three more hours. Goil wanted to see the
first of the gravitor tugs emerge with its load. Finally a ship
emerged from the cloud mass and headed for the station.

"What is it carrying?" Goil asked, looking at the tremendous mass of
incandescent material being towed a mile behind the tug.

"Tungsten," I said. "Would you like to see our cache?"

I steered the little observation ship past the station. When we
arrived at the cache area I eased the speed of the ship until it was
barely moving around among tremendous masses of various metals. Goil
recognized small spheroids of gold and silver. I pointed out other
metals, some in greater quantities than others, all floating in space,
with thick cables connecting them. I saw Goil looking at the cables
curiously.

"Keeps them from drifting apart," I said.

For another twenty minutes we cruised around the cache. Goil said
only a word now and then. He was visibly impressed by the mountains of
metal all around, all representing untold potential wealth. I think he
better understood how such an expensive operation so far from Earth
could be quite profitable.

"You may wonder," I said, "just how I located this cache. There are
several little transmitters among the piles. I just home in on any one
of them. Each metal cache has its own frequency. Gold, silver,
tungsten, beryllium...."

Goil nodded. "Let's go back to the station."

* * * * *

Goil called for Orrin and me. We entered his temporary quarters.

"Sit down," he said. He suggestively waved smoke away from his face,
and Orrin stubbed out his cigar.

"Mr. Orrin," Goil started, "you may have one of the top asteroid
mining stations, but in spite of your fine production record, there
seem to be some discrepancies we