Page:Popular Science Monthly Volume 88.djvu/56

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WING to the hazardous nature of work in gaseous mines, a demand has been growing for a practical, portable electric lamp. That an electric lamp would be safe to use has been well recognized, because it would be made so that it would not ignite inflammable gases and would produce a uniform light regardless of atmospheric conditions. The perfection of the efficient tungsten lamp in miniature sizes and the devel'opment of small, efficient, light weight storage batteries has resulted in the design of the long-desired miner's electric lamp.

The prime feature of this lamp is that it has been made thoroughly safe to use. By adequate insulation of the entire circuit, placing all terminals and contacts inside of locked and sealed steel cases and providing automatic means for extinguishing instantly the glow of the filament, should breakage of the lamp bulb expose it to the air, this lamp has been made both safe and rugged. The outfit complete weighs but three and three-quarters of a pound, of which three and a half pounds arc carried on the belt and four ounces on the cap. The battery will light tue lamp twelve hours per charge and can be relied on to furnish light at least ten and three-quarter hours per charge at the end of one year's service.

The bulb is held at the focal point between contact springs, which maintain it constantly under stress, so that, in case of a blow otherwise only sufficient to chip or partly break the bulb, it will be completely shattered by the springs and will drop clear of the contact. Sufficient space is provided between the reflector and glass cover to keep broken lamp parts from short-circuiting the spring contacts. This prevents the possibility of ignition even if the cap lamp is seriously damaged amid explosive gases.

By means of this improved lamp, a miner may work amid a steady white light, and feel secure from devastating explosions.

N attachment for the rear wheel of an automobile, by which the automobile may be made to serve as a winch has recently been brought out. Four hooks are attached by straps to the tire. The hooks are bent at their inner ends, and a coiled spring passed through the loops thus formed, so that the hooks point towards the hub. A cable is wound about the loops and securely fastened.

When the motorist finds himself mired, it is a simple matter to pass one end of the rope about the nearest tree or telephone post and then to start the car on the first speed. The revolutions of the wheel wind up the rope, and act as a very powerful winch. The car is soon out.