Bob grinned as Jack, his task concluded, turned around to face him.
“Well, Mr. Reporter,” he said. “You’re becoming quite expert at making these daily reports.” Jack laughed. “Just the same,” he commented, “it’s not a bad idea, that of these individual portable sets. No matter where Dad is, it’s a pretty safe bet that he heard me.”
Each member of the expeditionary party was provided with a small but powerful portable radio set of wide range. Thus whenever, as in the present instance, anybody was absent on side expeditions by tuning in at a fixed hour each night and morning, he received a resume of the day’s activities and of any startling events occurring during the night, which those remaining at the headquarters encampment broadcasted.
These sets were the boys’ pride. All three had had a hand in their manufacture. Each set was mounted in a cabinet the size of a portable typewriter case. It contained a regenerative tuner, a detector and one stage of audio amplification, and was a powerful receiver with two tubes. The secret of its smallness was that it operated on ordinary little flashlight batteries. The head set clamped into the inside of the lid when not in use. Closed, the cabinet could be carried by means of a handle. The whole business weighed less than ten pounds. Throw an insulated wire over a tree, and one would be ready to listen-in.
Almost as compact, in its way, was the sending apparatus which now occupied a small collapsible table in one corner of the tent. Table and all, including the motor, fitted into the oblong box yawning emptily on the ground beneath at the present moment—a box two and a half feet by a foot in breadth and nine inches in height.
In its construction, the boys had labored to achieve an apparatus for both sending and receiving. When one spoke, the vocal impact against a sensitive diaphragm closed reception, but the minute the voice of the speaker ceased, the instrument again was ready to receive.
It was over this apparatus that the boys planned to broadcast a concert for the benefit and mystification of the Kikuyus, and now that his evening bulletins had been radioed to his father Jack got busy with final preparations. Moving their small talking machine into position and attaching the audion, he laid the records he and Frank had dusted within reach for quick adjustment. All was now ready, and the only thing he waited for was Matse’s report from a reconnaissance into the village that their loudspeaker and apparatus concealed in the council tree had neither been discovered nor tampered with.
The council tree arrangement which had been installed the previous night at a late hour, when all in the village were asleep, consisted of one of the portable receiving sets with loop aerial and loudspeaker attachment.
Really, the loop aerial had not been necessary. An insulated wire thrown over the topmost branches of the tree would have been sufficient. Installation of the small loop aerial had been considered by Bob as a “piece of dog.” But Frank and Jack had insisted upon it, in the desire to make their proposed concert a superlative success. And they considered the clearness of the voice from the air during Wimba’s trial ample justification of the extra trouble to which they had gone.
Frank returned as Jack finished his preparations, with the announcement that Matse reported the entire village assembled expectantly beneath the council tree about a great fire.