STOPPING LEAKS. 



101 



the under bed, and the whole lowered into the pit and over 

 the main fissure (Fig. 63). After being carefully set in place 

 and rammed down, the space all round between the stone and 



uide 

 box 



Water Level in Dock 



28 feet below Sea Level 



Surface of Rock 39 feet below Sea Level 



Pit cut in Rock to 43-9 

 below Sea Level 



Invert 



Sub-Invert 



FIG. 62. 



the rock was closely packed with wedges well driven down. 

 This checked the flow, and enabled the water to be lowered. 

 Other parts of the same fissure, but which could be got at as 



soon as the water was lowered, 



were covered with flat stones 

 in the manner shown in Fig. 

 64. The course followed was 

 altogether satisfactory, and ulti- 

 mately enabled the water to be 

 completely brought under con- 

 trol, and the lock removed to 

 the extent required without 

 further difficulty. What leakage remained was collected in a 

 channel cut in the extra masonry, and led away to drainage 

 pipes. 



Stock Ramming. Mr. W. R. Kinipple, M.I.C.E., strongly 



tones o--cr Main Fissurt 



SECTION ON F F 



FIG. 63. 



Drain Pi t 



FIG. 61. 



