This is one of the first incandescent bulbs manufactured by the Edison Electric Light Co. It is probable that this bulb was used to conduct experiments with electric lighting. The filament is thought to be made of carbonised paper or bristol board, and forms six small coils. On the base of the bulb, someone, perhaps Edison himself, wrote Menlo, N.J., 1878. The bulb came to the Museum from the Ontario Hydro Museum, which had received it from the Science Museum in London, England.