Cutaway diagram, map, and accompanying text describing the construction of an electric motor-powered rapid transit subway that would have run through the basements of “fire-proofed buildings constructed along the line”. Despite shallow excavations of only nine-and-a-half feet, the blurb promises “no perceptible vibrations from the passage of trains”. Hmmm.

nyplmaps:

The City Railway Company, rapid transit passenger lines [189-?]

This map shows the location of a proposed underground rapid transit line and an “alternative line” in Manhattan and the south west Bronx. There is text describing the proposed line and a section cut diagram of transit tunnels.