He glanced at his watch and saw that it was almost eleven o’clock, the hour when he had promised to open his receiving station and wait for a message from his chums. He decided that this was as good a spot as any, and unpacked the apparatus from his knapsack, adjusting and extending the rods from which his aerial could hang.
As he looked about for a good place to stand his rod, he caught a glint of something bright in the tangled grass near him.
He bent and picked it up, and was amazed to find that it was a small gold locket. Hastily he opened it, and there staring at him from the two compartments, were pictures of Ruth and her grandfather!
Garry almost shouted with glee. They had come this way, and the next step was to determine in which direction they had gone.
That, however, must wait for a moment, for he wanted his chums to know that he was safe, and hence must wait for a time for a message from them.
But when he spread out his apparatus, a pang struck him. Part of the detector, the most essential part of the receiving apparatus, was missing!
Garry examined it closely and saw that it had been broken; and when he took thought, he remembered the haste in which the boys had packed their knapsacks, his among them, when they left the lumber camp some days before.
Inwardly the boy berated himself for his stupidity in setting out on this search without first seeing that all his apparatus was in perfect order.
The detector, sometimes known to users of the radio as a “cat’s whisker,” is a thin wire with a point attached to it, extending from the sounding posts to a piece of galena or silicon. This detector is used for this reason: The voice waves that are sent out through a radio transmitter are too faint to be heard by the human ear unaided by a mechanical apparatus.
The detector or “whisker” is moved about on the silicon until it strikes a sensitive spot, and in this way the air waves are brought into proper tune, and may be heard through the receiving ’phones.