BETHLEHEM MORAINE 265 



plate 13). During the existence of the Geological Survey of New Hamp- 

 shire, Professor Hitchcock, the State Geologist, examined the field, in 

 company with Agassiz, and concurred fully with him in this interpretation 

 of the evidence, although dissenting from Agassiz regarding some "other 

 speculations concerning the existence of glaciers in the neighborhood'• , 

 which were never published. 3 Hitchcock carried the idea of local glacia- 

 tion further, describing in his report a number of alpine glacier systems, 

 of which the most important was the Ammonoosuc glacier. This, accord- 

 ing to his view, moved northwestward and westward down the Ammo- 

 noosuc Valley, after the Canadian ice-sheet had receded from the moun- 

 tains, and redistributed the drift, building lateral and terminal moraines 

 in the neighborhood of Littleton, Bethlehem, and Twin Mountain House. 

 Cases of transportation of rocks from parent ledges northwestward — or 

 opposite to the regional movement — were cited. Thirty years later Dr. 

 Warren Upham, revisiting the district in which, as a young man, he had 

 worked as Hitchcock's assistant on the State Survey, discovered that the 

 morainic features were more satisfactorily referred to a local White Moun- 

 tain ice-cap than to a valley glacier. 4 Typical morainic drift with knob 

 and kettle topography was reported by Upham to extend in a nearly con- 

 tinuous belt from near the Twin Mountain House westward past Beth- 

 lehem to Littleton — a distance of 12 miles. ISTo new evidence was offered 

 in support of the view that the ice had moved from the mountains north- 

 ward to the moraines, but the previous observations of Hitchcock were 

 accepted, and the view was adopted that near the close of the last Glacial 

 epoch, when the continental ice-sheet had withdrawn from the district, 

 local snowfall on the White Mountains was sufficiently great to maintain 

 an ice-cap, around the periphery of which a distinct moraine was built. 

 A careful reading of the evidence presented by these three observers 

 does not convince one of the validity of the conclusions which they drew 

 regarding the source of the ice and the direction of its movement. For 

 example, Agassiz compared the moraines north of Bethlehem to the re- 

 cessional moraines of the Bhone glacier ; yet the topography of the Beth- 

 lehem district bears no resemblance to the Alpine valley. The supposed 

 source of the glacier — in the White Cross Eavine, on the northwest side 

 of Mount Lafayette — was apparently not regarded by Agassiz as suffi- 

 ciently important to be investigated and described, although at the time 

 when he wrote, as now, it was recognized that local glaciers carve out 

 peculiar bowl-shaped ravines or cirques at their heads. According to 



3 C. H. Hitchcock : Geology of New Hampshire, vol. 3, 1878, pp. 233-234. 



4 Warren Upham : Moraines and eskers of the last glaciation in the White Mountains. 

 Amer. Geologist, vol. 33, 1904, pp. 7-14, 



