Figure 22.—Broadside published after commencement of work on the Thames Tunnel, 1827.
(MHT collections.) [Transcription] of the text is presented in the Transcriber's Notes below.
Figure 23.—Vertical section through Brunel's shield. The long lever, x, supported the wood centering for turning the masonry arches of the lining. (Law, A Memoir of the Thames Tunnel.)