Early development of the incandescent lamp

This paper discusses, many inventions referred to lamp development patent by Sawyer and Man conjointly and some by Sawyer separately. In July 1878, Sawyer, Man, and five other individuals formed the Electro-Dynamic Light Company. Westinghouse brought under its control practically all of the important incandescent electric lamp patents except those of the Edison company. Edison had secured a patent about lamp bulb. Upon the expiration of the Edison patent, the Westinghouse company resumed manufacture of the all-glass globe type of lamp. When the lamp business outgrew the capacity of the West 23rd Street factory, it was transferred to a new factory in Bloomfield, New Jersey.