Page:Popular Science Monthly Volume 88.djvu/925

 Popular Science Monthly

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��Strange Mineral Spring Deposit in a Nevada Desert

OXE might study this desert photo- graph a long time before reaching the conclusion that it pictured the deposit of a mineral water spring, and a very small spring at that. The spring is situated on the southern border of South Carson Lake in western Nevada and is known as Allen's Springs. The flow of water is less than one-half gallon a minute, but in this very arid country even this meager supply is important as it represents the only drinkable water within a radius of over twenty miles.

The strange looking deposit is a yellowish porous mass of tufa, chiefly carbonate of lime, which has been left as the waters have evaporated in the desert sun. In addition to this tufa from the spring, there are thinner incrustations of similar material that were deposited from the waters of the now extinct Lake Lahonton which, in prehistoric times, was a lake of enormous dimensions. No definite conclusion can be reached as to the time in years that has elapsed since this lake reached its maximum area, except that geologically speaking the existence of the lake was recent — perhaps seventy-five or one hun- dred thousand years ago.

��strain these oil-laden cells, the oil bursts out, often as a visible spray and usually perceptible to our sense of smell, and often as a greasy film on the fingers. As shown in the accompanying photo- graph, the peel may be so bent as to rupture a large number of these cells at

���A miniature explosion occurs when the oil from an orange peel is ignited

one time, and to fill the air with an oily mist. If, at the moment of bending, a lighted match be applied by an assistant a decided explosion will follow. This experiment is most successfully per- formed in a darkened room or in a room wholly dark except for the light from the match.

���As the waters from a Nevada spring evaporated, a strange deposit was left. It is yellow, porous tufa

��Orange Peel Oil Is Explosive

EVERYBODY knows the flavor of orange peel, but not everybody knows what causes that flavor. It is due to the oil contained in little cells in the rind. If the peel is bent so as to

��Air Raids Involve Problems

Hard to Solve ONDON'S problem of placing anti-aircraft guns is a serious The farther away from London they are stationed, the greater the number re- quired to make the passage across the fortified zone sufificiently perilous. On the other hand, the nearer the guns are brought to the city, the more restricted is their action for fear of inflicting injury on those they are intended to defend. A possible solution to this problem is the employment of mobile guns. The use of aircraft as a defense against air attacks has been officially stated to be inefficient by itself. The difficulties to be met are not regarded as insuperable, however, and great hopes are placed in future developments along that line.

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