24 PROFESSOR P. F. KENDALL AND MR E. P>. BAILEY 



narrow ridge, and the contemporaneity of the local and foreign glaciation of the district 

 can scarcely be doubted. 



The next stage in the history, so far as it can be unravelled, was marked by an 

 advance of the great ice sheet blocking the intake A, and also the escape by way of the 

 Lammer Loch channel to the east. At the same time the Heriot pass, far to the west, 

 happened to be available, so that drainage took place along the ice front cutting the 

 channel BDE. A partial retreat allowed the water to follow another course B D G, and 

 further retreat allowed of lateral escape simultaneously from two points along this 

 channel leading to the excavation of the cross contour courses D H and F I. That these 

 two did come simultaneously into operation is almost certain from the fact that the bottom 

 of the lateral channel leading out at D is slightly deeper than the high-level entrance to 

 F G, so that had D H been formed first, F I could not have been reached by water, and 

 therefore could not have been excavated at all. On the other hand, it is impossible to 

 imagine F I cut first, for its exit could not have been closed again by the ice sheet 

 without also closing that of D H. Further, there is direct evidence in the field that 

 the original depressions at I) and F, before either was breached, must have been at 

 approximately the bottom level of the groove B F G. Once these lateral escapes were 

 opened and cascades had formed on the steep hill slopes, the channels were rapidly 

 deepened. F I seems to have offered a freer escape at first, for it evidently carried the 

 greater bulk of water. 



We did not make a particular study of the deposits of the local glaciers of the 

 Lammermuirs. No doubt they supplied a considerable proportion of the material of the 

 great Lammermuir terraces of sand and gravel, but we consider that the chief memorial 

 of their existence is the protection which they provided to the upper part of the range 

 from the ravages of marginal stream action. At the same time the following description 

 by Sir Archibald Gkikie * seems to indicate that the local glaciation may have been 

 responsible for the production of a certain amount of morainic material. We quote in 

 full : " Between the heath and the rock there intervenes, on the higher parts of the 

 Lammermuir range, a mass of rudely stratified rubbish, to which, in the progress of the 

 survey, the provisional name of Surface Wash has been given till its true history is 

 better understood. It' lies along the ridge between the head of the Hopes Water and 

 the Kilpallet Heights. It is usually a sandy clay or earth more or less distinctly 

 stratified, and containing pieces of greywacke and shale, often well striated. Though 

 frequently different in character from the rocks immediately adjacent, these stones 

 cannot have come from any great distance. The deposit is only a few feet in thickness. 

 Perhaps it is to be regarded as the remanie of the boulder clay, washed down and 

 reassorted by rain, though the comparatively small number of the striated stones and 

 the irregularity of the striation have sometimes suggested that this accumulation may 

 be as old as the snowfields of the glacial period." 



* Geology of East Lothian, 1806, p. 65. 



