Tunnel shields and the use of compressed air in subaqueous works - Copperthwaite, W. C. (William Charles) (New York, Van Nostrand Co., 1906)
Appendix: A. A chronological list of events connected with tunnelling by means of a shield or of compressed air. B. Some English patents relating to tunnelling with shield and compressed air, 1818 to 1904.
"Greathead, and the introduction of shield work in recent years."--Chapter I.
Mode of access: Internet.
Keywords: Greathead, James Henry, -- 1844-1896.; Tunneling