The Underground Railways of London During the Blitz

In 18 65, the london pneumadic dispatch railway opened. The driving power is at holborn, and consists of two 24 horse power steam engines. And the immense circular fan revolves with great rapidity in an air chamber. This can be used either for blowing the trains through the tubes or literally sucking them back again. It might or might not have been intended as a model for an atmospheric railway.