Edison screw

invention of

Skyway Library, King County Library System (historylink.org) The Skyway Library is located in Skyway, an unincorporated area of King County between Seattle and Renton. The library began in 1953 when residents decided they wanted a permanent library instead of just bookmobile service.

Edison screw (Wikipedia) Edison screw (ES) is a standard lightbulb socket for electric light bulbs. It was developed by Thomas Edison (1847–1931), patented in 1881, and was licensed in 1909 under General Electric’s Mazda trademark. The bulbs have right-hand threaded metal bases (caps) which screw into matching threaded sockets (lamp holders). For bulbs powered by AC current, the thread is generally connected to neutral and the contact on the bottom tip of the base is connected to the “live” phase.