Page:Popular Science Monthly Volume 92.djvu/936

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��Popular Science Monthly

��Which Is the "Dead" Lamp on a

Series Circuit? An Automatic

Gut-Out Tells

���culties by providing a device which auto- matically cuts the fibrient of a "dead" lamp out of the circuit and places a re- sistance in the circuit so as to maintain it closed and balanced. Thus the remaining lamps in the circuit are enabled to glow on. The inventor winds a resistance coil around a resistance carrier within the lamp in such a manner that the breaking or burning out of the filament will blow out a fuse. The spring held by the fuse is released, thus introducing the resistance in the circuit and bridging over the gap caused by the burning out of the filament. The trouble and inconvenience formerly caused by the burning out of a single filament in a circuit can thus be reduced to a bagatelle.

��Fu^ecircvjit

��Lightir\g clrcviit

��Figs. 2, 3 and 4 show the three circuits embodied in the lamp separately and Fig. 1, below, a diagram of the complete lamp

��WHEN an incandescent lamp which forms part of a series circuit burns out or when its filament breaks, all other lamps on that circuit are extinguished. The circuit must be bridged around the defective lamp. As all the lamps of the circuit are extinguish- ed, it is a tedious task to find the exact lamp which caused th.e break. Each one has to be tested separate- ly until the burnt-out bulb has been found. Not until then can the circuit be restored, either by substituting a good lamp for the one burnt out or by bridging over the gap in the circuit.

The incandescent lamp recently invent- ed by F. Wybaillie, of New York, and shown in the accompanying illustration, aims to overcome these diffi-

��Clad in such armor our soldiers would indeed look like Martians or super-men

��The Fifty- Seventh Variety of Armor for the Modern Soldier Appears

THE soldiers of old went forth to fight clad in cumbersome and expensive armor, which, while serving as a protection, nevertheless hindered them from putting forth their best fighting strength. To-day, Martin Jelalian, an inventor of Rhode Island, has made it possible for a soldier to be pro- tected by armor. He is one of several dozen inventors who have reinvented the coat of mail.

The device is a bullet-proof metallic structure which sur- rounds the body and extends from the top of the shoulders to below the thighs. This steel coat consists of two like parts held together across the chest by means of straps. Hooks at- tach the coat to semi-cylindrical pieces of metal which fit closely about the upper part of the leg, and are fastened be- hind by straps. The inner surface of the armor is padded. The head is protected by a lined mask composed of the same metal.

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