“Let’s try!” agreed Tom, and calling to Rawlins to wait where he was they hurriedly disconnected their instruments and connected the odd resonance coil in position.
“Now, say something, Mr. Rawlins,” called Tom.
Anxiously the boys waited but no response came although the boys could hear a very faint buzzing sound.
“Well, that evidently is a failure,” said Tom, “but just the same these fellows wouldn’t have had it aboard unless there was some use for it.”
“I’ll tell you what I think,” said Bancroft. “My idea is they used that in the air, when they were running on the surface or just awash. You might get the words from under water then, or perhaps it wasn’t used for undersea work.”
“We’ll have to try that—when Mr. Rawlins gets here,” replied Tom.
Presently Rawlins appeared and the boys told him of their new plans. In a few minutes the submarine had risen to the surface and the boys prepared to test the resonance coil.
“First we’ll try it in the air,” announced Tom. “Walk over on the island there, Mr. Rawlins, and see if we can get you.”
Accordingly, the diver slipped into the sea and a few moments later his head appeared near shore and for the first time the boys experienced the strange sensation of seeing a man walk ashore from beneath the water. That they could receive messages with the resonance coil through the air was soon proved to their satisfaction, and telling Rawlins to go under water and walk about in different directions the two boys and their companions, who were fully as much interested, prepared for the final test. But this was a dismal failure and chagrined and disappointed the boys gave up at last.
“If we hear any one under water we’ll have to find them some other way,” Tom announced. “We just get that funny buzz we used to hear in New York. And I’ll bet anything that was the men talking under water. But if we hear anyone talking in the air we can locate them all right.”