found him seated at the calculating machine,
continuing a problem which already filled several pages of his notebook.

"'Smatter, Steve? So glad to see a calculator and some paper that you
can't let them alone?"

"Not exactly--just had a thought a day or so ago. Been computing the
orbit of the wreckage of the _Arcturus_ around Jupiter. Think we should
salvage it--the upper half, at least. It was left intact, you know."

"H ... m ... m. That would be nice, all right. Dope enough?"

"Got the direction solid, from my own observations; the velocity's a
pretty rough approximation though. But after allowing for my probable
error, it figures an ellipse of low eccentricity, between the orbits of
Io and Europa. Its period is short--about two days."

"Isn't it wonderful to have a brain?" Brandon addressed the room at
large. "The kid's clever. Nobody else would have thought of it, except
maybe Westfall. Let's see your figures. Um ... m ... m. According to
that, we're within an hour of it, right now." He turned to the pilot and
sketched rapidly.

"Get on this line here, please, and decelerate, so that the stuff'll
catch up with us, and pass the word to the lookouts. Stevens and I will
take the bow plates.

"That's a good idea," he went on to Stevens, as they took their places
at main and auxiliary ultra-banks. "Lot of plunder in that ship.
Instruments, boats, and equipment worth millions, besides most of the
junk of the passengers--clothes, trunks, trinkets, and what-not. You're
there, bucko!"

"Thanks, Chief," ... and they fell silent, watching the instruments
carefully, and from time to time making computations from the readings
of the acceleration and flight meters.

"There she is!" An alarm bell had finally sounded, the ultra-lights had
flared out into space, and upon both screens there shone out images of
the closely clustered wreckage of the _Arcturus_. But both men were more
interested just then in the mathematics of the recovery than in the
vessel itself.

"Missed it eight minutes of time and eleven divisions on the scale,"
reported Stevens. "Not so good."

"Not so bad either--I've seen worse computation." Thus lightly was
dismissed a mathematical feat which, a few years earlier, before the
days of I-P computers, would have been deemed worthy of publication in
"The Philosophical Magazine."

* * * * *

Director Newton was called in, and it was decided that the many small
fragme