On October 21, 1879, current was turned into the lamp and it lasted forty-five hours before it failed. A patent was applied for on November 4th of that year and granted January 27, 1880. All incandescent lamps made today embody the basic features of this lamp. Edison immediately began a searching investigation of the best material for a filament and soon found that carbonized paper gave several hundred hours life. This made it commercially possible, so in December, 1879, it was decided that a public demonstration of his incandescent lighting system should be made. Wires were run to several houses in Menlo Park, N. J., and lamps were also mounted on poles, lighting the country roads in the neighborhood. An article appeared in the New York Herald on Sunday, December 21, 1879, describing Edison’s invention and telling of the public demonstration to be given during the Christmas holidays. This occupied the entire first page of the paper, and created such a furor that the Pennsylvania Railroad had to run special trains to Menlo Park to accommodate the crowds. The first commercially successful installation of the Edison incandescent lamps and lighting system was made on the steamship Columbia, which started May 2, 1880, on a voyage around Cape Horn to San Francisco, Calif. The carbonized paper filament of the first commercial incandescent lamp was quite fragile. Early in 1880 carbonized bamboo was found to be not only sturdy but made an even better filament than paper. The shape of the bulb was also changed from round to pear shape, being blown from one inch tubing. Later the bulbs were blown directly from molten glass. [Illustration: DYNAMO ROOM, S. S. COLUMBIA. The first commercial installation of the Edison Lamp, started May 2, 1880. One of these original dynamos is on exhibit at the Smithsonian Institution.] As it was inconvenient to connect the wires to the binding posts of a new lamp every time a burned out lamp had to be replaced, a base and socket for it were developed. The earliest form of base consisted simply of bending the two wires of the lamp back on the neck of the bulb and holding them in place by wrapping string around the neck. The socket consisted of two pieces of sheet copper in a hollow piece of wood. The lamp was inserted in this, the two-wire terminals of the lamp making contact with the two-sheet copper terminals of the socket, the lamp being rigidly held in the socket by a thumb screw which forced the socket terminals tight against the neck of the bulb. [Illustration: ORIGINAL SOCKET FOR INCANDESCENT LAMPS, 1880.] [Illustration: WIRE TERMINAL BASE LAMP, 1880. This crude form of lamp base fitted the original form of lamp socket pictured above. This lamp is in the exhibit of Edison lamps in the Smithsonian Institution.]