the gas between the roof of the cavity and the surface of the accumulating water; when the force of the compression reaches its maximum, it drives the water from the chamber up through the tube, from which it escapes in some instances to a distance of thirty feet in a vertical
Fig. 3.
direction. After the pent-up water and gas have escaped, the spouting ceases for a short time until the conditions are favorable for its repetition, when the process is continued. The springs secured by this method are the Vichy, Geyser, Champion, Kissingen, and the so-called magnetic. In depth they vary from fifty to three hundred feet. So far as the temperature of the springs is concerned they are practically isothermal, the maximum being 52° and the minimum 40° Fahr.; and in no instance are they affected by external causes, both their flow and temperature being uniform throughout the year. From the fact that the perpendicular iron tubes, through which the waters flow from certain wells, are capable of communicating magnetic properties to steel, the term magnetic springs has been applied to them in various sections of the country. Notwithstanding assertions to the contrary, the water from such springs has been pronounced totally devoid of any properties of a magnetic character by those who have investigated this phenomenon. All of the magnetic properties connected with such springs reside in the iron tubing, which becomes magnetic when placed in the ground in a vertical position in localities where the conditions are favorable; this result is said to be more likely to be attained if the tube is inclined a few degrees to the north.
