Wow! Especially the second link is amazing. Many of the pics immediately make me think "how the heck did that guy get into our house to take these pics???????" For example, one of his 1890-1910 era light switch controls our balcony light.
I think this could be the infamous German Walter socket. The 4 scraping contacts at the bottom are 2 for neutral and ground each. Invented around 1905 or so and used until about the 1930ies when the 4prong 3ph plug w/o neutral came up. I was told that these sockets were sometimes mounted upside down, resulting in the scrapers loosing contact from the weight of the cord.
Re: Nostalgia#137556 07/18/0303:20 AM07/18/0303:20 AM