with numerals. He could hear the operator's low mumble of disappointment as he lifted the "set" from his head, disarranging more than ever his already tousled hair. Then the listener drew closer, for a sudden little sound, half-grunt, half-cry, had broken from McKinnon's lips.
The phones were once more held down hard on his ears as he stooped forward, this time wide-awake.
The coherer had stirred and quivered into life. A faint and febrile little shower of ticks was pounding minutely against his ear-drums. Some one was "sending."
He reached out and drew up the form-pad before him as he listened. The call was coming clearly now, repeated again and again. "Pt-Ba," "Pt-Ba," came the query through the night. McKinnon, as he listened and "tuned up" to the other man's tensity, could recognise the nature of the "send" as one would recognise the accent of a Westerner in Boston or a Londoner in Dublin. It was the unmistakable yet undefinable inflection and cadence of a navy man. It was an American battleship of some sort, calling Puerto Locombia.
McKinnon was on his feet again, tingling with excitement. He threw down his switch-
