RADICAL RADIO

Hawke's Bay Tribune, Volume XVII, 24 November 1927, Page 8

RADICAL RADIO

HEARD 500 FEET DOWN. SOLID ROCK PENETRATED Washington Oct. 15. Radio waves will penetrate 500 feet or more or rock strata, it was discovered in testa conducted by the United States Bureau of Mines in a Colorado metal mine. Experiments were made by Dr. A. 8. Eve. director of the Department of Physics McGill University, who is conducting a study of the possibilities of various methods of geophysical prospecting for the location of underground mineral deposits. RECEPTION IS CLEAR. The first test was conducted at a depth of 220 feet in the Caribon mine of the American Mining and Prospecting Company at Caribon, Colo where, by means of a loop, a strong and clear reception was obtained of a musical concert given at Denver 50 miles away. The experiment was conducted with a superheterodyne set with nine electron tubes. The evi denco pointed strongly to the conclusion that this clear reception was due to the penetration by the radio waves of the solid rock strata. A “mushy reception” was obtained from Denver in the next series of experiments conducted at a depth of 550 feet. Reception, however was as good as could be obtained above ground at the time of making the test, the night being unfavourable for general radio reception. This test was conducted at the end of a cross cut reached with many turns and 200 feet main shaft. FURTHER STUDY PLANNED. It is believed possible that the radio waves excited the conductors in the shaft, and these in turn excited th e conductors in the shaft, and these in turn excited the rails and pipes, which brought the radiation to within 70 feet of the experimenters and that the strong amplification of the radio apparatus enabled the radiation to bridge the gap. This, Dr. Evo considers is improbable but not impossible. He was impressed, however, with the -fact that the loop did not point toward neighbouring conductors or along the tunnels, but it did point at both levels within a few degrees of th e source at Denver. Further investigations, it is felt at the bureau, should include a comparison of the penetration of radio waves from a distance exceeding many wavelengths, and of radio waves generated at a distance less than a wavelength.