However, the Edison conduits once in use, both the public and even the telephone, telegraph and ticker companies acknowledged their feasibility. So used had people become to this sort of thing that even the most competent electrical authorities of the time doubted extremely whether Edison's scheme of an underground system could be made either a scientific or a commercial success, owing to the danger of great loss through leakage. In those days such electrical transmission as existed - this of course related largely to telegraphy - was accomplished by means of a veritable forest of poles and wires augmented by the distribution equipments of fire alarm, telephone, burglar alarm and stock ticker companies. The district selected for lighting was the area - nearly a square mile in extent - included between Wall, Nassau, Spruce, and Ferry Streets, Peck Slip and the East River in New York City. The development of an adequate underground conduit proved also most serious. New York City, the construction of the first successful direct-connected steam dynamo. Edison began, in the spring of 1881, at the Edison Machine Works, Goerck Street, With the experience gained by an experimental system at Menlo Park, Mr. The announcement of the invention of the carbon filament lamp was first made to the public in December, 1879. Edison's electric-lighting system was taken on October 21, 1879, when he discovered that if a carbonized cotton thread were substituted as a burner for the platinum wire of his earlier lamp, the slender and apparently frail carbon was mechanically strong, and also durable under the action of the electric current. Here every night in winter thousands upon thousands of people throng to theaters and cafés. Times Square, New York, at night, with Broadway on the left, a curving ribbon of white light. *Illustrations by courtesy of New York Edison Co., unless otherwise indicated. Such a lamp necessarily had a small illuminating power compared with that of the arc light, which was the only electric light then in commercial use. The first marked accomplishment in operative detail was a lamp with a platinum wire burner of high resistance, protected by a high vacuum in an all-glass globe, and with the leading-in wires sealed into the glass by fusion. Edison, at his experimental laboratory at Menlo Park, New Jersey, where he had already invented the carbon telephone transmitter and many other things, undertook the task of devising a general system for the generation, distribution and utilization of electricity for lighting and power purposes.