mber of
insoluble salts. Even the nitrate violated the long-held rule that "all
nitrates are soluble"--it wouldn't dissolve. Yet it was chemically more
active than gold.

But its physical constants were the most surprising. It melted at 2800 deg.
centigrade, a very high melting point indeed. Very few metals are solid
at that temperature. But the tensile strength test made with a standard
bar they finally turned out by means of a carbaloy tool, gave a reading
of more than one million, three hundred thousand pounds per square inch!
It was far stronger than iron--stronger than tungsten, the strongest
metal heretofore known. It was twice as strong as the Earth's strongest
metal!

Fuller whistled in awe. "No wonder they can make a plane like that when
they have such a metal to work with." The designing engineer had visions
of a machine after his own heart--one in which half the weight was
_not_ employed in holding it together!

It was a little later that they got communication through to Earth, and
the men went to the power room. The television screen was struggling to
form a clear image despite the handicap of forty million miles of space.
In a moment it had cleared, though, and they saw the face of Dr. Arcot.
He showed plainly that he was worried about the startling news that had
reached him already, sketchy though it was. After brief though warm
greetings, his son rapidly outlined to him the full extent of their
discoveries, and the force that Earth would have to meet.

"Dad, these Kaxorians have planes capable of far more than a thousand
miles an hour in the air. For some reason the apparatus they use to
propel them in space is inoperative in air, but their propellers will
drive them forward faster than any plane Earth ever saw. You must start
at once on a fleet of these molecular motion planes--and a lot of the
gas Wade developed--you know how to make it--the animation suspending
gas. They don't have it--and I believe it will be useful. I'll try to
develop some new weapons here. If either of us makes any progress along
new lines--we'll report to the other. I must stop now--a Lanorian
delegation is coming." After a few words of farewell, Arcot severed
connections with the Earth and arose to await the arrival of the
visitors.

Since the return of the Terrestrians to the _Solarite_, a great crowd of
Venerians had gathered around it, awaiting a glimpse of the men, for the
news had spread that this ship had come from E