There is also another nice interactive one based on a map from 1843. "B.R. Davies made detailed maps of London from about 1840 to 1869, and this is one of his earliest. Buildings, parks, roads, bridges, and important sites are identified." http://maps.google.com/gallery/details?id=zDoXIAU5tGiw.k4Op2POUgsdc&hl=en