W. Upham—Work of Prof. H. C. Lewis. 157 
which composes the deposit is filled with glacier-scratched boulders 
and fragments of all sizes and shapes.” 
From its lowest point in Pennsylvania, where it crosses the 
Delaware 250 feet above the sea-level, this terminal moraine of the 
ice-sheet extends indiscriminately across hills, mountains and valleys, 
rising over 2000 feet above the sea in crossing the Alleghanies, and 
attaining the maximum of 2580 feet on the high table-land farther 
west, being there “finely shown at an elevation higher than any- 
where else in the United States.” 
Preliminary outlines of Professor Lewis's work on the glacial drift 
of England, Wales and Ireland are given in his papers in the Reports 
of the British Association for 1886 and 1887; and the first of these 
also appeared in the American Naturalist for November, and the 
American Journal of Science for December, 1886, and in this 
Magazine for January, 1887. Their most important new contribution 
to knowledge consists in the recognition of the terminal moraines 
formed by the British ice-sheets, which Lewis traced across Southern 
Treland from Tralee on the west to the Wicklow Mountains and Bray 
Head, south-east of Dublin; through the western, southern and 
south-eastern portions of Wales; northward by Manchester and along 
the Pennine Chain to the south-east edge of Westmoreland ; thence 
south-easterly to York and again northward nearly to the mouth of 
the Tees, and thence south-eastward along the high coast of the 
North Sea to Flamborough Head and the mouth of the Humber. 
It is a just cause for national pride that two geologists of the United 
States, Lewis in Great Britain in 1886, and Salisbury’ the next year 
in Germany, have been the first to discover the terminal moraines 
of the ice-sheets of Europe. Like the great moraines of the interior 
of the United States, those of both England and Germany lie far 
north of the southern limit of the drift. 
Another very important announcement by Professor Lewis relates 
to the marine shells, mostly in fragments and often worn and 
striated, found in morainic deposits and associated kames 1100 to 
1350 feet above the sea on Three Rock Mountain near Dublin, on 
Moel Tryfan in Northern Wales, and near Macclesfield in Cheshire, 
which have been generally considered by British geologists as proof 
of marine submergence to the depth of at least 1350 feet. These 
shells and fragments of shells, as Lewis has shown, were transported 
to their present position by the currents of the confluent ice-sheet 
which flowed southward from Scotland and Northern Jreland, 
passing over the bottom of the Irish Sea, there ploughing up its marine 
deposits and shells, and carrying them upward as glacial drift to 
these elevations, so that they afford no testimony of the former 
subsidence of the land. The ample descriptions of the shelly drift 
of these and other localities of high level, and of the lowlands of 
Cheshire and Lancashire, recorded by English geologists,? agree 
1 American Journal of Science, III. vol. xxxv. pp. 401-407, May, 1888. 
2 Quart. Journ. Geol. Soc. vol. xxx. 1874, pp. 27-42; xxxiv. 1878, pp. 383- 
397; xxxvi. 1880, pp. 3851-5; xxxvil. 1881, pp. 351-69; and xlii, 1887, pp. 73- 
120; also, Grow. Mac. Dec. II. Vol. 1. 1874, pp. 193-197. 
