roblems to be met.
I should say, though, that the one big trouble with all solar engines,
eliminating the obvious restriction that they decidedly aren't
dependable for night work, is the difficulty of getting an area to
absorb the energy. If I could get enough area, I could use a very low
efficiency and still have cheap power, for the power is absolutely free.
The area problem is the greatest difficulty, no doubt."

"Well," Arcot junior said quietly, "I think you have a fairly good area
to use, if you can only harness the energy it absorbs. I have really
developed a very efficient solar engine. The engine itself requires no
absorbing area, as I want to use it; it takes advantage of the fact that
the Earth is absorbing quintillions of horsepower. I have merely tapped
the power that the Earth has already absorbed for me. Come here."

He led the way down the corridor to his laboratory, and switched on the
lights. On the main laboratory bench was set up a complicated apparatus
of many tubes and heavy bus bar connectors. From the final tube two thin
wires ran to a long tubular coil. To the left of this coil was a large
relay switch, and a rheostat control.

"Turn on the relay, Dad, then slowly rotate the controller to the left.
And remember that it is rather powerful; I know this doesn't look like a
solar engine, and nine o'clock at night seems a peculiar hour to
demonstrate such a thing, but I'll guarantee results--probably more than
you expect."

Dr. Arcot stepped up to the controls and closed the switch. The lights
dimmed a bit, but immediately brightened again, and from the other end
of the room came a low, steady hum as the big transformer took up the
load.

"Well, from the sound of that ten K.W. transformer there, if this engine
is very efficient we ought to get a terrific amount of power out of it."
Dr. Arcot was smiling amusedly at his son. "I can't very well control
this except by standing directly in front of it, but I suppose you know
what you're doing."

"Oh, this is a laboratory model, and I haven't gotten the thing into
shape really. Look at the conductors that lead to the coil; they
certainly aren't carrying ten K.W."

Dr. Arcot slowly rotated the rheostat. There was a faint hum from the
coil; then it was gone. There seemed to be no other result. He rotated
it a bit more; a slight draught sprang up within the room. He waited,
but when nothing more startling occurred, he gave the rheostat a sharp
turn.