at the head of Haybuni Beck. 
At first Lake S taint ondale 
overflowed by tlie marginal 
•channel of Pye Rigg Slack 
(Plate XII.) into Lake Hay- 
burn. The retreat of tlie ice 
opened an outlet for Lake 
Staintondale by the Rudda 
Road col, at the same time 
that the waters of Lake Hay- 
burn began to be discharged 
by Cowgate Slack (Fig. 10). 
A temporary retreat caused 
the cutting of Hardhurst 
Slack, but its intake was soon 
•closed by a slight readvance 
of the ice, and Cowgate Slack 
Again was brought into o])era- 
tion, and continued the main 
overflow for a long period. 
Meanwhile Lake Staintondale 
liad cut through a second col 
in the intervening spur, form- 
ing the Tofta Road overflow, 
but further retreat threw this 
out of action, and the two 
lakes became confluent. 
A further retreat of the 
ice eastward freed a col on 
the long spur bounding Lake 
Hayburn-on the south, whicli 
was low^er than the Cowgate 
intake, and a new channel. 
Ringing Keld overflow (Fig. 
10), began to be formed along 
the edge of the ice. Further 
recession gave advantage to 
the new route, which developed 
