Back when the bat-signal was still illuminated by candle light, a non-electronic wielding vigilante roamed the streets, hunting down such villains as Jack the Ripper.
Marc Tan created this awesome piece titled “Gotham by Gaslight,” visualizing the image of Batman as seen through the eyes of 19th century Gotham.
This is not an original idea, http://en.wikipedia.org/wiki/Gotham_by_Gaslight.