The Sun Electric Company
The Sun Electric Company, of Woburn, Massachusetts, developed a lighting system in the late 1880s that was the creation of Marmaduke M. M. Slattery1. The picture to the far left is their 16-candle power multiple series lamp. The picture to the right of the lamp shows their socket. Details of the lamp and socket are not known. In the lamp picture the upper portion "shows a device by means of which lamps in groups may be operated with safety on constant current or arc light circuits—each lamp being supplied with one of these individual cut-outs, in case of failure of a lamp, the resistance in the brass is automatically switched into circuit, thus taking up the current of the defective lamp."

Slattery moved to Fort Wayne, Indiana in 1887 to work for the Fort Wayne Jenney Electric Light Company. He developed a system there and the incandescent lamp is shown below2. It can be seen that the socket represented is that of the "Fort Wayne Jenney." Fort Wayne acquired the Slattery patents and then purchased the entire assets of the Sun Electric Company as well as the Slattery Incandescent Company, of New York4.

The William J. Hammer Collection of Historical Incandescent Electric Lamps contains five Sun manufactured lamps. These are: 1887-340, 1887-376, 1888-361, 1888-372 and 1888-373. The details of these lamps can be found on this web site.

Acknowledgement
I am grateful to Jerry R. Westlick for providing a copy of Reference 1.

References
1) "The Sun Electric Company's System and Appliances," Electrical Review, Vol 11, No 2, Sep 16, 1887.
2) "The Slattery Induction System," Western Electrician, Vol 2, No 7, Feb 18, 1888, pg 73.
3) M. M. M. Slattery, "Alternating vs. Continuous Currents," Western Electrician, Vol 2, No 12, Mar 24, 1888, pp 152-154.
4) "The Affairs of the Fort Wayne Electric Company," The Electrical World, Vol 14, No 8, 1889, pg 134.