how many more of
these we can get built in other parts of the world."

They spoke that night to all the stations on the radio net, describing
in detail what they had begun, what they were confident it would do.
Professor Larsen's words were relayed to his colleagues in Stockholm.
They estimated they could begin work almost immediately on six
projectors. Others, elsewhere in the country, were quite probable.

In his conversation with Pasadena, Professor Maddox warned, "We have not
yet been able to make tests with the big projector. Our only work so far
has been with the laboratory models, but they were highly successful."

"That's good enough for us," said Dr. Whitehead, director of the
Pasadena work. "Everything we've done here has failed so far. A direct
chemical approach seems out of the question. We'll start with one, but I
think a dozen projectors, at least, are possible for this area."

Pasadena also reported a new radio contact with Calcutta, and promised
to pass the word on to them and to Tokyo. When they closed down the
transmitter after midnight, Ken totaled the number of projectors
promised with reasonable certainty of having the promises fulfilled.
There were eighty.

"It may take a year," his father said, "or it may take 10 years, but now
we know, without a doubt, that we can someday get our atmosphere back as
it was before the comet."

Chapter 20. _Reconstruction_

On the twentieth of January the comet reached its closest approach to
Earth. It was then less than three million miles away. In the realm of
the stars, this was virtually a collision, and if the head of the comet
had been composed of anything more than highly rarefied gases it would
have caused tremendous upheavals and tidal waves.

There were none of these. Only the dust.

Ken arose at dawn that day and went into the yard to watch the rising of
the golden enemy a little before the sun came over the eastern hills. He
doubted whether anyone else was aware it was closer today than it had
been before, or ever would be again. He doubted there would be much
scientific interest in the event, anywhere in the world.

In the observatory, he opened the dome and adjusted the telescope to
take a few pictures and spectrograms. He remembered when he had done
this, a long time ago, with high excitement and curiosity, and he
remembered later times when he had looked up with a bitter hate in his
heart for the impersonal object in the sky.

No