Letter from Sir Marc Isambard Brunel to Isambard Kingdom Brunel

Brunel reports on the re-construction of the Thames Tunnel and describes an incident, 'Having heard from those men who were in the shield to the last moment...in the course of a few minutes roaring noise was heard [indicating] that the ground having been washed at the Back of the Polings, the Polings were thrown from their place ... and the protection entirely broken away.'