The foregoing are but a few of the innumerable instances where the local lines of drainage have been disturbed, and even permanently changed, by the glacial deposits. Almost every lake in the glaciated region is a witness to this disturbance of the established lines of drainage by glacial action, while in numerous places where lakes do not now exist they have been so recently drained that their shore-lines are readily discernible. An interesting instance of the recent disappearance of one of these glacial lakes is that of Runaway Pond, in northern Vermont. In the early part of the century the Lamoille River had its source in a small lake in Craftsbury, Orleans County. The sources of the Missisquoi River were upon the same level just to the north, and the owner of a mill privilege upon this latter stream, desiring to increase his power by obtaining access to the water of the lake, began digging a ditch to turn it into the Missisquoi, but no sooner had he loosened the thin rim of compact material which formed the bottom and the sides of the inclosure, than the water began to rush out through the underlying and adjacent quicksands. This almost instantly enlarged the channel, and drained the whole body of water oft 3 in an incredibly short time. As a consequence, the torrent went rushing down through the narrow valley, sweeping everything before it; and nothing but the unsettled condition of the country prevented a disaster like that which occurred in 1889 at Johnstown, Pa. Doubtless there are many other lakes held in position by equally slender natural embankments. Artificial reservoirs are by no means the only sources of such danger. The buried channel of the old Mississippi River in the vicinity of Minneapolis is another instructive example of the instability of many of the present lines of drainage. The gorge of the Mississippi River extending from Fort Snelling to the Falls of St. Anthony at Minneapolis is of post-glacial origin. One evidence of this is its narrowness when contrasted with the breadth of the valley below Fort Snelling. Below this point the main trough of the Mississippi has a width of from two to eight miles, and the faces of the bluffs on either side show the marks of extreme age. The tributary streams also have had time to wear gorges proportionate to that of the main stream, and the agencies which oxidise and discolor the rocks have had time to produce their full effects. But from Fort Snelling up to Minneapolis, a distance of about seven miles, the gorge is scarcely a quarter of a mile in width, and the faces of the high, steep bluffs on either side are remarkably fresh looking by comparison with those below; while the tributary gorges, of which that of the Minnehaha River is a fair specimen, are very limited in their extent.