the principal icy mass moved straight onwards in a direct line towards the hill of Chasseron, g (precisely opposite f), where the Alpine erratics attain their maximum of height on the Jura, that is to say, 2,015 English feet above the level of the Lake of Neufchatel, or 3,450 feet above the sea. The granite blocks which have ascended to this eminence g, came from the east shoulder of Mont Blanc, h, having travelled in the direction b, f, g.
When these and the accompanying blocks resting on the south-eastern declivity of the Jura are traced from their culminating point g, in opposite directions, whether westward towards Geneva, or eastwards towards Soleure, they are found to decline in height from the middle of the arc g, towards the two extremities i and k, both of which are at a lower level than g, by about 1,500 feet. In other words, the ice of the extinct glacier, having mounted up on the sloping flanks of the Jura in the line of greatest pressure to its highest elevation, began to decline laterally in the manner of a pliant or viscous mass, with a gentle inclination, till it reached two points distant from each other no less than 100 miles.
In further confirmation of this theory, M. Guyot observed that fragments derived from the right bank of the great valley of the Rhone, c, d, e, are found on the right side of the great Swiss basin or strath, as at l and m, while those derived from the left bank, p, h, occur on the left side of the basin, or on the Jura, between g and i; and those again derived from places farthest up on the left bank and nearest the source of the Rhone, as n o, occupy the middle of the great basin, constituting, between m and k, what M. Guyot calls the frontal or terminal moraine of the eastern prolongation of the old glacier.
A huge boulder of talcose granite, now at Steinhoff, ten miles east from k, or Soleure, containing 61,000 cubic French feet, or equal in bulk to a mass measuring 40 feet in every
