I wore it on my left hand, and there it still is.” And Jack held up the device for inspection. “The inventor said it had a receiving radius of ten miles. It may mean a lot to us before we see the end of this adventure.”
The ring-radio of Inventor Bender is worthy of more extended mention and, inasmuch as later it was to play a noteworthy part in the adventures of the boys, perhaps it would be well to describe it at this time.
In the first place, Inventor Bender’s ring-radio was not, strictly speaking, his own invention, but rather an adaptation of a similar device earlier invented by Alfred G. Rinehart, a young radio wizard of Elizabeth, N. J.
The young inventor had not patented his device, but to an interviewer representing The Radio Globe of New York he had given a sketchy description of its operations, suppressing details. This had come to Inventor Bender’s attention. With no desire to steal another’s idea, but merely for his own amusement, he had taken up the matter and devised his own ring-radio, and this it was which he had sold to Jack.
The head phones and connecting wires from the ring to the phones and to aerial and ground were intact in his traveling bag, Jack already had ascertained. Whoever had searched the bag for possible
concealed weapons had not considered it important to take them.
“Even my umbrella is strapped to my bag,” said Jack. “You remember Inventor Bender said I could connect a lead to the metal stem of the umbrella for aerial and stick a screwdriver into the earth for my ground connection. Of course, there is no earth here, but salt water will do even better.”
The ring of this set was the coil, slender, only slightly more than an eighth of an inch in diameter, and encircling the finger. The mounting comprised the controls and measured only 1 × 1-2 × 7-16 of an inch. These measurements included the brightly polished bakelite panel on which were mounted a diminutive crystal detector and small switch control connected with the coil by nine taps, permitting of nine different tuning adjustments by means of a movable band making connections in the heads of nine tiny brass studs set in the panel in the form of a semicircle. The whole was no larger than many ornate rings, and resembled one in appearance.
“Mr. Bender said it would receive on wave lengths up to and including 550 meters,” Jack explained. “This trawler undoubtedly has radio. In fact, I saw the aerial when we came aboard. Probably, sooner or later, it will open communication with the radio at the smugglers’ cove, and we can hear it.”
“But any conversation would be in code,” protested Frank. “Besides, they might use a very high meter wave length, and your set would be unable to receive.”