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Show DISCOVERING GOLD BY 'PHONE. A new way of prospecting has been tried experimentally and is reaching the point where it 1 practically useful. The method is based on the differences in the electrical conductivity of the earth due to the presence of ore deposits. Most ores are much better conductor of electricity than the soil and rocks, although some others are almost insulators. insu-lators. . i - In making use of .these facts to locate beds of ore two electrodes are grounded about 100 yards apart. In the circuit is an induction coil with a glass condenser end two spark gaps. The current as it passes through the ground is tested by two telephone receivers re-ceivers connected to portable electrodes, which are usually grounded about seventy sev-enty feet apart. i The make and break of the current in passing through the ground is heard in the telephones as ticks. As the electrodes attached to the telephones tele-phones are moved about, the variations in the intensity of tapping in the telephones tele-phones give an Indication of the presence pres-ence and position of the ore deposits. Although the method is not out of the experimental stage, yet it seems to promise much for itself in the future. Collier' Weekly. |