1884

The base was further modified by eliminating the collar used for holding and twisting the bulb into a socket.  Otherwise, the base remains the same as the previous base (i.e., it included a copper threaded shell (which served as one contact terminal) and a straight-sided or tapered copper contact at the bottom which served as the second terminal, all over the plaster of paris insulator.  Since the plaster of paris collar above the base had now been eliminated, the light bulb had to be hand-held by the glass bowl to place and turn the base into the female threads of the socket.

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