452 SE\\"ELL : OVERFLOW CHANNEL IN NEWTON DALE. 
however, found by which we can gauge the dimensions of " Lake 
Wheeldale " between this and the shore-Hne cut in the Kehaways 
rocks as already described, until we come to Moss Slack, when 
we note the latest level of its intake to have been 675 feet above 
O.D. 
The unrestrained mass of water discharging through and 
over the soft sandy Estuarine series would quickly wear away 
the five miles of river course between Fen Bogs and Raindale 
Beck, depositing its spoil as the delta in Lake Pickering. 
To summarise, we are able to locate four distinct periods : — 
(a) Ice drainage at 825 feet, and possibly up to 900 feet, 
steady and gradual, ice increasing or at its maximum, temperature 
at its lowest. 
(b) Lake shore at 775 feet, showing drainage at this level 
gradual and lasting some time, temperature higher. Ice receding, 
possibly period of the earliest Newton Dale overflow. 
(c) Moss Slack, level 675 feet, showing signs of a continual 
river channel draining a largely increased area through a decreased 
*' Lake Wheeldale," and discharging its waters into Newton Dale, 
as described by Professor Kendall. 
{d) Professor Kendall's account of the latest southern 
drainage over Fen Bogs sill (525 feet). Ice rapidly receding ; 
water-flow much more violent, especially immediately following 
the close of the period described as (c), Newton Dale being 
continuously eroded through its entire length down to its present 
level. 
" The evidence of overflows prove that at the maximum 
extension of the ice, a lake was held up in Eskdale to an altitude 
of over 725 feet " (Kendall). Again, page 18, vol. XV., part I., 
of the Yorkshire Transactions, " Lake Wheeldale drained by 
Moss Slack at 675 feet." But Two Howes Rigg is just on the 806- 
foot contour, and the river draining through Newton Dale probably 
flowed between the ice and Two Howes Rigg {over the above 
Moss Slack) at a much higher altitude than 675 feet, see (b). 
