1873.] WARD — LAKE-DISTRICT GLACTATION. 435 



not more than a mile wide, between Dodd and Barf. The result 

 of this seems to have been that much of it was forced over the fells 

 between Whinlatter and "Wythop, the higher tops beiug alone 

 unenveloped. 



The Buttermere glacier, though large, probably could not com- 

 pare with that of Borrowdale, fed by larger areas of fell. Its 

 source was derived from Fleetwith behind Honister Crag, some of 

 the ice passing on the north and some on the south of the Crag. 

 Lower down it was added to by glaciers shed from the mountains 

 and combes on either side, especially by those of the High-Stile and 

 Bed-Pike range. 



About Scale Force the western side of the glacier would seem to 

 have divided on either side of Mellbreak, part turning due west and 

 joining the ice flowing from Great Borne and Gale Fell, down the 

 valleys on the western side of Mellbreak. At the northern end of 

 Mellbreak the glacier-sheet would seem to have again divided, the 

 main mass continuing down the vale of Lorton, but a branch finding 

 an outlet to the west by way of Loweswater. Very possibly, how- 

 ever, at the time of greatest ice-extension, the ice may more or less 

 have enveloped and passed over the oblong tract of highish ground 

 (from 1000 feet to 1300 feet) between Loweswater and Lorton. 



The long straight Ennerdale valley was also at this period in 

 great part filled with ice, the higher feeding-grounds being the 

 north and western slopes of Kirk Fell, Great Gable, and Green 

 Gable, while the many combes along the Pillar range on the south 

 side of the valley each contributed its glacier to the main stream. 

 The ice seems to have passed over Latter Barrow at the east end of 

 Ennerdale Lake, and to have exerted much pressure on emerging 

 from the valley between Crag Fell on the south and Great Borne on 

 the north. 



The overriding of parting ridges by the confluent-glacier ice is 

 also very evident on the western side of the Ullswater valley. 



2. Mild Interglacial Period.' — The existence of at least one mild 

 interglacial period is, I think, shown by the following considerations*. 



a. Sand and Gravel mounds.— The mounds of stratified sand and 

 gravel already mentioned occur up to 800 feet at least without con- 

 taining large boulders or angular blocks ; above this height, up to 

 1050 feet, similar sand and gravel mounds contain boulders. In 

 both cases, however, boulders, often of large size, are found upon 

 the mounds. 



The mounds were formed by the meeting of tides and currents 

 during a submergence of the land, and they are consequently formed 

 for the most part at the ends of valleys. The question, however, is, 

 whether a mild period had come on before the submergence began, or 

 whether the country went down beneath the sea ice-clad, and the 

 climate was changed to a mild one before its complete re-elevation. 

 Now the sand and gravel mounds without boulders imply an absence 

 of floating ice ; and the fact that boulders are found on but not within 



* I cannot find any facts in thin district to .suggest a cutting up of tlie Ice- 

 sheet Period by several mild seasons. 



