Thomas Edison talking about the invention of the light bulb - 1920s

Описание: Thomas Edison talking about the invention of the light bulb, late 1920s

"Before starting experiments on the incandescent electric light system, many memorndums were drawn up as to a general system that would permit a subdivision of the light into small units analogous to gas jets and with commercial economy superior to the prevailing gas system. The thought was, if it was to be successful, all the units must be worked in multiply. This necessitated the creation of lamps of very high resistance to diminish the enormous investment in copper if necessary, if lower resistance lamps were to be used. (For the safety??) This necessitated identifying hair-like filaments of high air-resistance material. On October twenty-first 1871, numerous experiments resulted in the production of a small unit lamp of comparatively enormous resistance. The filament being? under conditions of great stability after this result, I knew the problem approached commercial solution. As these lamp experiments continued, other parts of the general system was actively experimented upon. The dynamo, as then invoked, was extremely inefficient; the loss approaching fifty percent due to some misunderstanding among electricians which I never comprehended. However, these experiments produced a dynamo of which ninety percent of the energy was useful. Then meters for measuring the current were used by thousands of customers and also a host of accessories like underground conduit, circuits, sockets, et cetera were necessary to make a complete system of distribution, all of which was accomplish..."