Even moreso than that, many of the lights in New York still run on genuine relays. You can easily hear them at many street corners in Manhattan, happily thunking away. (The New York Subway is also still powered almost exclusively by relays, even to do complex things like monitor train speed. It's both impressive and disturbing to see what they were able to accomplish a hundred years ago without modern computing hardware.)
Any recommended links on where one could read more on the NY Subway systems you mention? I'm fascinated by pre-electronic computing, and this sounds like a particularly interesting example.
