_June 19._--The bricklayers left off work, but, on enquiring into the cause, I learned there was no other but to have a libation upon the new arrangement of piece-work. _June 29._--Gave positive directions to cut only 4½ to 5 inches thick at a time at the front of the top cells, instead of 9 inches, as they had done for some time. _July 3._--The great question is, does the clay undulate at its surface? We should have some reason to apprehend that it does so, because at the beginning we had not proceeded many feet into the clay when we struck again into the gravelly stratum. The surface of the clay must therefore have sunk at that particular spot; which circumstance seems to warn one of the need of great vigilance and great prudence in the progress of the enterprise. [Sidenote: Cofferdam burst at Woolwich.] [Sidenote: Warning for us.] _July 10._--A cofferdam burst yesterday at the works at Woolwich, having blown up from the foundation. How cautious this should make our men! The cofferdam may be repaired, and very easily too, but an irruption into the Tunnel--what a difference, particularly at this early period! [Sidenote: Carelessness of the miners.] _August 10._--Found the lowest cell of No. 1 left by the workmen _without a single poling against the ground_. This is indeed a most unjustifiable neglect. _August 12._--At six this morning completed 205 feet. [Sidenote: Observations on the bad effect and consequence of driving on as is done.] _August 21._--This piece-work has not been productive of much effect as to quantity of work. As to quality it is very questionable. A work of this nature should not be hurried in this manner. Fewer hands, enough to produce 9 feet per week, would be far better than the mode now pursued _from necessity_, but not from inclination on my part. Great risks are in our way, and we increase them by the manner the excavation is carried on. The frames are in a very bad condition. _September 5._--It is much to be regretted that such a work as the Tunnel should be carried on by the piece. Obliged to drive on, no time is left to make any repair, or to recover any lost advantage. Isambard is most active. Mr. Beamish shows much judgment in his exertions, and zeal in his attendance.[14] [Sidenote: Water breaking in at back of frames.] [Sidenote: How to check it. Isambard’s exertions.]