e
secrets of a long and productive life. Why attempt to do more than can
be accomplished efficiently? There is always tomorrow. I am more
interested in that which we are now building than you can possibly be,
since many generations of the Rovol have anticipated its construction;
yet I realize that in the interest of our welfare and for the progress
of civilization, today's labors must not be prolonged beyond today's
period of work. Furthermore, you yourself realize that there is no
optimum point at which any task may be interrupted. Short of final
completion of any project, one point is the same as any other. Had we
continued, we would have wished to continue still farther, and so on
without end."

"You're probably right, at that," the impetuous chemist conceded, as
their craft came to earth before the observatory.

* * * * *

Crane and Orlon were already in the common room, as were the scientists
Seaton already knew, as well as a group of women and children still
strangers to the Terrestrials. In a few minutes Orlon's companion, a
dignified, white-haired woman, entered; accompanied by Dorothy,
Margaret, and a laughing, boisterous group of men and women from the
Country of Youth. Introductions over, Seaton turned to Crane.

"How's every little thing, Mart?"

"Very well indeed. We are building an observatory in space--or rather,
Orlon is building it and I am doing what little I can to help him. In a
few days we shall be able to locate the system of the Fenachrone. How is
your work progressing?"

"Smoother than a kitten's ear. Got the fourth-order projector about
done. We're going to project a fourth-order force out to grab us some
dense material, a pretty close approach to pure neutronium. There's
nothing dense enough around here, even in the core of the central sun,
so we're going out to a white dwarf star--one a good deal like the
companion star to Sirius in Canis Major--get some material of the proper
density from its core, and convert our sender into a fifth-order
machine. Then we can really get busy--go places and do things."

"Neutronium? Pure mass?" queried Crane, "I have been under the
impression that it does not exist. Of what use can such a substance be
to you?"

"Can't get pure neutronium, of course--couldn't use it if we could. What
we need and are going to get is a material of about two and a half
million specific gravity. Got to have it for lenses and controls for th