
Here's an interesting ad from the February 10, 1906 Ypsilanti Daily Press, from the Washtenaw Light and Power company.
Apparently, if you subscribe to the service, you can get unlimited refills of "Edison base lamps," (old-time incandescent bulbs with the familiar screw bottom). The company also offers adaptors for "T.H. [Thompson-Houston] bulbs," which were also known as "bayonet" bulbs. TH bulbs were invented in 1883 and the company merged with Edison in 1893 to form General Electric.




