Page:Popular Science Monthly Volume 50.djvu/43

Rh well-marked naked old moraines at least two miles in length, which sweep round to the volcano above referred to, and apparently connect with the terminal moraine of a small narrow glacier just east of the Whitney Glacier, and which may formerly have been an upper eastern branch of it. This, perhaps, is the Ash Creek Glacier, which lies on the northeast slope of the mountain, while the McCloud Glacier lies farther to the eastward.

The terminal moraines at the end of the Whitney Glacier, which are not, as in Swiss glaciers, clearly demarked from the end of the glaciers themselves, but form an exceedingly irregular and broken field of rocks and débris covering and burying the ice, with many sinks or basins and "kettles," enabled me to clearly understand the mode of formation of the "kettles" or deep holes, at times still filled with water, which are so marked in Massachusetts, near Salem and Marblehead, and also at the "Dumplings" on Canonicut Island near Newport, Rhode Island.

In his account of the McCloud Glacier of Mount Shasta in his entertaining Mountaineering in the Sierra Nevada, Mr. Clarence King states that for "at least a mile's width the whole lower zone is buried under accumulation of morainal matter. Instead of ending like most Swiss glaciers, this ice wastes chiefly in contact with the ground, and when considerable caverns are formed the overlying moraine crushes its way through the rotten roof, making the funnels we had seen."

These immense fields of morainal matter overlying and burying the melting edge of the glacier, here spreading out over the lower flanks of the mountain, were evident signs of the waning of the ice, the glacier having long since ceased to advance; and it enabled me, as never before, to understand that the peculiar hills and basins or kettles of the great terminal moraine of southern New England were formed by the irregular melting of the southern edge of the glacier, when through and under the mass of ice, perhaps not over from three to five hundred feet thick, ran subglacial streams and rivers, while here and there, owing to the uneven melting of the ice, immense masses of gravel and bowlders had fallen in, the material adjoining being rearranged into rounded kames, so characteristic of our New England scenery.

The rocks on the eastern side of the middle portion of the Whitney Glacier were rounded and polished, as much as such hard rock could well be, when the glacier was of greater volume than now. At present the ice has melted away from the sides of the rock overlooking it. So far as I could see from my point of view, the surface was not grooved or striated.

That the glacier was in motion was proved by the not infrequent distant explosions caused by the rupture of the ice near the