In order to understand the origin of the first incandescent lamp introduced by Thomson-Houston in the year 1884 it is necessary to briefly review the history of different companies. The Thomson-Houston Company had been formed in 1883 to produce dynamos and arc lighting; it succeeded the American Electric Company, which had been formed in the year 1880. American Electric was formed based on the patents of Elihu Thomson and Edwin J. Houston. A Lynn syndicate, which consisted of business men, including Charles A. Coffin, bought American Electric in 1883 and renamed it Thomson-Houston.
To continue this story it is necessary to consider some of the lamp companies initiated by William E. Sawyer and Albon Man. These two men started manufacturing low resistance lamps in the year 1878 in the newly-formed Electro-Dynamic Light Company. Because of friction between Sawyer and owners of the company, Sawyer then organized the Eastern Electric Manufacturing Company in 1879. In 1882 Eastern was reorganized as the Consolidated Electric Light Company. The Thomson-Houston Company owned a controlling block of Consolidated stock. Thomson-Houston began to produce an incandescent lamp, based on Sawyer-Man patents, by taking out a license from Consolidated.
The lamp and socket engraving shown to the left represents the Consolidated lamp as produced in 1886. It was scanned from a publication put out by E. H. Johnson2, President of The Edison Electric Light Company, in 1886, that indicated assumed infringements of Edison patents by competitive manufacturers. The original engraving had arrows pointing to various parts and indicated the Edison patents they supposedly infringed.
It appears that the lamp base and socket design for the Thomson-Houston lamp (based on Sawyer-man patents) resulted after thought was given to the making and breaking of the electrical circuit. The switch in the socket was described in an Electrical World article titled "A New Incandescent Lamp Switch". The article1 read:
"The principal objects to be attained in an incandescent lamp switch are a good contact and rapid make and break, so as to avoid sparking. Among the recent switches designed from this standpoint is that of the Consolidated Electric Light Company, of this city. The switch is shown in perspective in Fig. 1, and its action is apparent. The rectangular contact-maker lies flat against the lower spring when the lamp is turned off, but when it is desired to light up, the turning of the switch beyond a certain point causes it to snap quickly so as to make contact with the upper spring. In the same way the turning off is accomplished with a 'snap,' insuring a rapid break. The lamp bulb with its base is screwed to a solid bearing against the upper contact strip, making a firm contact and preventing a loose joint from being made by a jarring of the parts. Our illustration, Fig. 2, shows the lamp and socket combined."The lamp switch is shown below, while the lamp-socket combination is essentially similar to the combination shown above and will not be reproduced here.
References
1) "A New Incandescent Lamp Switch", The Electrical World, Vol VII, 1886, pg 142.
2) "The Edison Electric Light - The Legal and Commercial Status", E. H. Johnson, Oct 7, 1886.
3) "Statement of the Methods and Apparatus in Use at the Time the Department Was Closed", H. D. Burnett, Incandescent Lamp Department, Thomson-Houston Electric Company, Lynn, ca Aug 12, 1893.
4) "Notes on Development of the Carbon Incandescent Lamp at the Lynn Lamp Works of the Thomson-Houston Electric Company", Letter to F. W. Willcox dated April 12, 1911. This letter was sent in response to a request by Mr. Willcox, for use in connection with the U. S. Government Suit versus the General Electric Company.