On passing over the shallow German Sea from England to the Continent, the southern border of the Scandinavian ice-field is found south of the Zuyder Zee, between Utrecht and Arnhem--the moraine hills in the vicinity of Arnhem being quite marked, and a barren, sandy plain dotted with boulders and irregular moraine hills extending most of the way to the Zuyder Zee. From Arnhem the southern boundary of the great ice-field runs "eastward across the Rhine Valley, along the base of the Westphalian Hills, around the projecting promontory of the Hartz, and then southward through Saxony to the roots of the Erzgebirge. Passing next southeastward along the flanks of the Riesen and Sudeten chain, it sweeps across Poland into Russia, circling round by Kiev, and northward by Nijni-Novgorod towards the Urals."[BV] Thence the boundary passes northward to the Arctic Ocean, a little east of the White Sea. [Footnote BV: A. Geikie's Text-Book of Geology, p. 885.] The depth of this northern ice-sheet is proved to have been upwards of 1,400 feet where it met the Hartz Mountains, for it has deposited northern _débris_ upon them to that height; while, as already shown, it must have been over 2,000 feet in the main valley of Switzerland. In Norway it is estimated that the ice was between 6,000 and 7,000 feet thick. The amount of work done by the continental glaciers of Europe in the erosion, transportation, and deposition of rock and earthy material is immense. According to Helland, the average depth of the glacial deposits over North Germany and northwestern Russia is 150 German feet, i. e., about 135 English feet. As the deposition towards the margin of a glacier must be commensurate with its erosion near the centre of movement, this vast amount implies a still greater proportionate waste in the mountains of Scandinavia, where the area diminishes with every contraction of the circle. Two hundred and fifty feet is therefore not an extravagant calculation for the amount of glacial erosion in the Scandinavian Peninsula.