"NAA—NAA—P—A—X."
Over and over again he sent the call, while in the meantime the condenser built up its charge from the overflow of current from the turbine generator. Then the electrician opened a switch, and the roar outside diminished and finally ceased.
"We can't listen—with the tractor running," he fretted. "The static—from the discharge—would tear—our detector—to pieces." He threw in the receiving instrument. For a few moments the telephones spoke only the whisperings of the arctic aurora, and then suddenly the faint cry of the answering spark was heard. Bennie watched the words as the electrician's pencil scrawled along on the paper.
"Waiting for you. Why don't you send? N.A.A."
"They must have—called us before—while the discharge—was running down," muttered Atterbury. "I think we can send—with the condenser—now."
He picked up the scrap of yellow paper, read it over, and threw out into space the message which he did not understand.
"O. K. Wait. Thornton," came in reply.
Two hours later came a second message:
"P—A—X. Burke starts at daybreak. Expects reach you by nine P. M. Asks you to show large beacon fire if possible.
"THORNTON, N. A. A."