This bulb has a carbonized split Japanese bamboo filament and copper plated joints connecting the filament to the platinum inner leads. The base is similar to that of the previous lamp in production [see A14]
except that the cone-shaped copper ring is now eliminated as the second electrical contact terminal. It has been substituted with a straight-sided copper contact at the bottom of the base. The entire copper arrangement is constructed over plaster of paris. This bulb was manufactured about mid-1882. It is interesting to note that the base of this bulb will even fit into today’s sockets.
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