"Now swing your glass to the left," commanded the lieutenant, "and stop when you come to a little whitish patch almost hidden by trees."
"I have it," exclaimed Don.
"I think you will find in a few moments that our battery has it, too," commented the other, dryly. "You might not suspect it, but that insignificant little light spot is a part of the side of a building, and on that building has been erected——"
"The wireless plant," supplemented Don, eagerly.
By this time the telephone operator, with the receivers attached to his ears, was ready to transmit the captain's orders to the battery, while the senior officer in the observation post had his glasses leveled on the distance.
"How strange it is," reflected Don Hale, "that people some three miles away are moving unconcernedly about a certain building, totally unaware of the fact that within a moment or two they will be exposed to the most terrible danger!"
He lowered his binocular, for the captain was speaking.
"First piece," he commanded.
"First piece," echoed the telephone operator, speaking into the transmitter.
"Direction: wireless station; range five thousand yards."