SUUMAUlNi; TUNNKLINC; 231 



per day, all in the hard clay. No timbering had been necessary, 

 and except for the first 100 ft of the tunnel there was very 

 little seepage. On the afternoon of Oct. 21 water was observed 

 coming out from one of the diill holes in the heading, but no 

 attention was paid to it Shortly after a blast was fired, and 

 was immediately followed by a rush of water from the heading. 

 An unsuccessful attempt was made to check the flow, and the 

 pumps were started ; but they were unable to keep the water 

 down, and after seven hours' hard work the tunnel was aban- 

 doned. By the next morning the tunnel and shaft were full of 

 water. 



Several attempts were made to empty the tunnel ; but the 

 limited pumping capacity was not equal to the task, and it was 

 finally decided to install larger pumps. The pumping had, how- 

 ever, shown that about 1,000 gallons of water a minute was 

 coming through the leak. With the increased pumping plant 

 the tunnel was finally laid dry Feb. 13, 1892. Upon examina- 

 tion the head of the drift was found to be in the same undis- 

 turbed condition in which it was left when the water broke in 

 three months before. 



A brick bulkhead was built into the end of the brickwork 

 of the tunnel, and provided with a timber door for passage, and 

 two 10-in. pipes for the outlet of the water. With these open- 

 ings closed, the flow was checked sufficiently to allow the pla- 

 cing of pumps at the bottom of the shore shaft. Meanwhile the 

 pressure of the water against the bulkhead caused dangerous 

 leakage, and so after the pumps were in position the 10-in. pipes 

 were opened, relieving the pressure and allowing the water its 

 normal rate of flow. Trouble with the pumps now arose, and 

 after various stopjuiges and breaks the discharge pipe finally 

 fell, disabling the whole plant. It became necessary to close 

 the 10-in. pi|>e8 in the bulkhead and draw up the pumps. This 

 allowed the tunnel to again fill with water. 



After thoroughly overhauling the pumping machinery, the 

 contractor again laid the tunnel dry on March 19; and after 



