GEOLOGY. 299 



cock. On reaching the cleared land, there are striffi in the bottom of the 

 valley, pointing north 70 east, the agent of erosion being directed down the 

 valley. In three places, also, before reaching the main branch of White 

 Kiver, are found accumulations of detritus, stretching across a considerable 

 part of the valley, in the same manner as ancient terminal moraines are 

 found in the valleys of the Alps. These have been somewhat modified by 

 the subsequent action of Avater upon the surface. 



At Hancock the valley meets the valley of White River at right angles; the 

 strire also are at right angles, for another glacier descended the valley of 

 White River; and, like modern glaciers, these ancient ones united their forces 

 at the junction, and travelled the larger valley together, bending, in their 

 course, to all the sinuosities of the river, as the stria? curiously and clearly 

 manifest. 



Mr. H. had examined but one of the tributaries below, but there found (at 

 Rochester) the clear evidences that a glacier came down its valley to meet the 

 main one, which terminates near Stockbridge, where an immense terminal 

 moraine crosses the valley. The total length of this glacier, so far as investi- 

 gated, is eighteen miles, and each of the tributaries examined was about four 

 miles. The slope, in all, was gradual and uniform. 



A less stinking example of the traces of glacial action is found upon the 

 Otta Queechee, above Woodstock. Several miles further west, just east of 

 Bridgewater, is a more decided example. Still others may be found on 

 Deerfield River, running up to Searsburg, and at the Hoosac tunnel; at 

 Windham, on the head waters of Saxton's River; at Mount Holly, running 

 nearly east and west, on Black River; at Tinmouth, on Furnace Brook; and 

 at Huntington. Probably the Green-Mountain Range was once covered with 

 glaciers, on both sides, either before or after the drift period proper; for, in 

 all these cases, away from the valleys, the drift strise were found in abun- 

 dance, pursuing a course diagonally to, or at right angles with, the course of 

 the glaciers. If, as is probable, the glaciers existed before the drift, it would 

 not be strange to find that occasionally the traces of their existence had dis- 

 appeared, because the icebergs, etc., would wear away the striae. The inac- 

 cessibility of their localities, and the decomposing character of the White 

 Mountain rocks, made it less probable that glacier-marks would there be 

 found. Still, research might very likely discover their traces. 



OX THE THEORY OF IGNEOUS ROCKS AND VOLCANOES, 

 BY T. S. HUNT, F. R. S. 



In a note in the American Journal of Science for January, 1858, I have ven- 

 tured to put forward some speculations upon the chemistry of a cooling 

 globe, such as the igneous theory supposes our earth to have been at an early 

 period. Considering only the crust with which geology makes us acquainted, 

 and the liquid and gaseous elements which now surround it, I have endeav- 

 ored to show that we may attain to some idea of the chemical conditions of 

 the cooling mass, by conceiving these materials to again react upon each 

 other under the influence of an intense heat. The quartz, which is present 

 in such a great proportion in many rocks, would decompose the carbonates 

 and sulphates, and, aided by the presence of water, the chlorides, both of the 

 rocky strata and the sea, while the organic matters and the fossil carbon 

 would be burned by the atmospheric oxygen. From these reactions would 

 result a fused mass of silicates of alumina, alkalies, lime, magnesia, iron, 



