"Try it again," Snap urged. "Good God, Johnny, we've got to raise some Earth station! Chance it! Use the power—run it up full. Chance it!"
We were gathered in Grantline's instrument room. The duty man, with blanched grim face, sat at his senders. The Grantline crew shoved close around us. There were very few observers in the high-powered Earth stations who knew that an exploring party was on the Moon. Perhaps none of them. The Government officials who had sanctioned the expedition and Halsey and his confrères in the Detective Bureau were not anticipating trouble at this point. The Planetara was supposed to be well on her course to Ferrok-Shahn. It was when she was due to return that Halsey would be alert.
Grantline used his power far beyond the limits of safety. He cut down the lights; the telescope intensifiers and television were completely disconnected; the ventilators were momentarily stilled, so that the air here in the little room crowded with men rapidly grew fetid. All, to save power pressure, that the vital Erentz system might survive.
Even so, it was strained to the danger point. Our heat was radiating away; the deadly chill of space crept in.
"Again!" ordered Grantline.
The duty man flung on the power in rhythmic pulses. In the silence, the tubes hissed. The light sprang through the banks of rotating prisms, intensified up the scale until, with a vague, almost invisible beam, it left the last swaying mirror and leaped through our overhead dome and into space.
"Enough," said Grantline. "Switch it off. We'll let it go at that for now."
It seemed that every man in the room had been holding his breath in the chill darkness. The lights came on again; the Erentz motors accelerated to normal. The strain on the walls eased up, and the room began warming.
Had the Earth caught our signal? We did not want to waste the power to find out. Our receivers were disconnected. If an answering signal came, we could not know it. One of the men said:
"Let's assume they read us." He laughed, but it was a high-pitched, tense laugh. "We don't dare even use the telescope or television. Or electron radio. Our rescue ship might be right overhead, visible to the naked eye, before we see it. Three days more—that's what I'll give it."