Page:Walker (1888) The Severn Tunnel.djvu/101

46 on the 17th, nine strokes on the 18th, and gradually up to ten and a half strokes; the greatest speed at which we allowed this large pump to run being eleven strokes per minute.

After an hour’s pumping the water in the Iron Pit was lowered nearly 30 feet, and there was still sufficient leakage going on through the closed sluice and door to lower the water outside the Iron Pit (that is, the water which was in the heading and the other pit alongside) 6 feet. In six hours from the time of starting the pumps the water was down 88 feet in the Iron Pit, and 9 feet throughout the whole of the works.

After twenty-four hours pumping the water was down 121 feet in the Iron Pit, and 24 feet throughout all the workings, and four and a half hours later the Iron Pit was clear down to the stage over the sump, the water throughout the workings standing at a depth of 24 feet lower than it had been before we commenced pumping.

As soon as the stage was reached we took out the broken H-piece and lowered the new one, which had been provided to repair No. 1 26-inch pump. This pump was ready to work at midnight on the 16th. No. 1 was started and No. 2 stopped; the drop-valve was drawn out of the rising-main and the top valve of No. 2 pump put in its right place and properly secured. The two pumps were started together on the 19th, but another stoppage of six hours was necessary on that day to repair a broken