SUBMAKJM: TI-NNKLIXQ 233 



stream flowing from the north through a well defined channel 

 in red clay. This channel was ahout 13 ft above the grade of 

 tlu- tunnel ; and above it in every direction visible was a bed of 

 hard, dry, ivd clay, while immediately in front of the face of the 

 work was a hank of course gravel. Fig. 120 is a sketch of the 

 channel and stream where they entered the work. In this last 

 drawing the photograph has l>een followed exactly, no particu- 

 lar being exaggerated in the slightest. The water from this 

 stream was clear and pure; and a chemical analysis showed 

 that it was not lake water, but must come from some separate 

 source. 



While the engineer did not consider the difficulty of pro- 

 ceding along the old line insurmountable, it was decided to be 

 less difficult on the whole to go back from 150 ft. to 175 ft. and 

 dellci i the line to the north and upward, so as to pass over the 

 underground entrance. Instead of allowing the water to flow 

 at its normal rate and take care of it by pumping, the contrac- 

 tors desired to reduce the pumping, and to this end they con- 

 structed a bulkhead just west of the deflection toward the 

 south with a view of shutting off the water. The water, how- 

 ever, accumulated with a pressure of some 50 Ibs. per sq. in., 

 and [>enetrated the filling around the brick lining of the tunnel, 

 preventing the cutting through of the lining for the new line. 

 A second bulkhead was then built about 20 ft. west of the 

 first, but with not much letter results, for upon closing it the 

 water was found to leak through the brickwork for a long 

 distance west. Finally on Aug. 2, 1892, the contractors 

 lifted their pumps and allowed the tunnel to fill again with 

 water. 



No further work was done on the tunnel by the contractors, 

 although they continued work on the lake shaft for some 

 months. Difficulties had, however, arisen here, which will be 

 dex,-ril>ed further on; and finally a disagreement arose between 

 the contractors and the city over the delay in prosecuting 

 the tunnel work and over one or two other questions, which 



