ooo 



Fig. li. View acToss the valley from the left abutment of the lower or greater ilaiii. The 

 width of the valley is here about 165 feet, with the earth walls ri.^ing abruptly lii' feet on 

 (iitlier siile. The soil is a glai-ial ilepiisit. sand |)rcdoiiiinating'. 



Fig. 7. View up the channel of the outlet at the greater dam. The depth of the valley 

 is shown by the altitude of the right abutment in the background. The evidence of the 

 ascending erosion line is in the foreground. 



