Progress of the work—1883. pumps were running twelve strokes per minute, I ordered them slowed down to ten. I was particularly anxious that there should be no panic.
A messenger was sent over by the last ferry-boat, to order the men on the Gloucestershire side of the river to at once commence to build a head-wall of brick in cement across the finished tunnel, west of the Sea-Wall Shaft. The men worked all the night and the next day, and completed the head-wall, leaving only a door 3 feet square at the top; but the water never rose so high as to reach the bottom of this head-wall. On the morning of the 11th the water had risen against the pumps to the height of 52 feet. On the 12th, the pumps, still working steadily, held the water at 132 feet from the surface.
A council of war was held, and it being the opinion of all that the inburst of the water might be from a subterranean reservoir, which would shortly exhaust itself, and that we should only have the same quantity of water ultimately to pump that we had before the inburst occurred, it was decided to continue the pumping for two or three weeks longer. After holding it a depth of 132 feet from the surface for two days, the pumps began to gain slowly. By the 22nd they had gained 9 feet 9 inches, and by the 26th, 13 feet.
The cubical contents of the tunnel and other works filled by the water, while the pumps were continually pumping at the rate of 11,000 gallons per minute, was accurately measured; and we found