voice interrupted. "I kept
Dr. Austin away from you until I felt that there was some hope. I didn't
want you to have another disappointment."

"As I got your idea from Mr. Wolf, it seems to me that the Smithsonian
might be glad to back you in further experiments," said Austin.

Roger's thin face flushed as it was apt to do when his work was under
discussion. "This is mighty kind of you, Dr. Austin, but my work has
gone beyond the experimental stage. I'm ready to erect Solar Power
Plants if I can find the money."

"Rog, you're not ready!" cried Ernest, with unusual vehemence. "You've
no idea of the troubles you'll be up against when you try actually to
erect a working plant, in a hot country."

"I'm not afraid," returned Roger shortly. "One thing is certain, I'm not
going on experimenting any longer."

"My understanding of your device is, that it is practical only in
tropical or semi-tropical climates," said Austin.

"This first device is, yes," answered Roger shortly. "If I can ever get
this one launched, I shall take up other climates."

Austin eyed Roger keenly for a moment, then he said suddenly,

"Why don't you let me see your plans? We might possibly have something
to say that would interest you."

"Oh, of course! I wish I had some of them here. And it's too late to go
up to the laboratory to-night."

"Wait a moment, Roger! Wait a moment," exclaimed Ernest. "Praying that
we'd get to this point to-night, I brought down a set of drawings." He
unlocked a drawer of the table and pulled out a roll of paper.

Roger spread some of the sheets on the table and the black, the yellow
and the sandy heads bent over them.

"This," began Roger, "is the general ground plan of a plant designed to
produce about 50 horse power. This detail here, which looks like a
design for a glassed-in hot bed for early cabbage, is the heat absorber.
It consists of a trough lined with some insulating material, covered
with two layers of ordinary window glass. Under this window glass I flow
crude oil, which absorbs the sun's heat as it comes through the glass. I
get some remarkable temperatures, right here in Eagle's Wing. Here is a
month's thermometer readings during July."

Austin studied the table thoughtfully. "The heated oil is the fuel for
a low pressure engine. What engine do you use?"

"One of my own design. Here are the drawings."

Austin bent over these with absorbed interest and for an hour Roger
answered his questions.