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"A Lamp In Reserve"
Text on blotter reads: Also: At the same time Americans began adopting electric lights, they also began adopting a new form of transportation–the automobile. Automotive lighting did not immediately benefit from electric lamps however. Early carbon filaments were too brittle to withstand severe shock and vibration. They were also quite dim and difficult to make to exact electrical and optical specifications. So early cars used oil or acetylene lamps. The development of lamps with ductile tungsten filaments in the years around 1910 changed the situation. Tungsten filaments could be made small and bright, and they proved tougher than carbon. Placed at the focal point of a parabolic reflector (as in the headlight of the car in this blotter), a small tungsten lamp could throw a beam bright enough to be useful. And unlike oil or acetylene units, electric lamps did not need refueling. They did need to be replaced occasionally though. The chest referred to in this blotter was a convenience package containing a variety of replacement lamps for headlights, tail lights and panel lights, all the spare bulbs a motorist might need. Early automotive lamps did not last as long as today's sealed beam or halogen lamps, and since streets were generally lighted only in urban areas drivers were encouraged to carry spare lamps just as they carried spare tires. Notice that an electrical company rather than an auto parts supplier sent out this blotter.
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