THE GLACIAL DRIFT. 6I7 



probability, an ancient erosion cliannel of the Wisconsin river, wliioii, 

 becoming blocked during the glacial times, was never after regained. 

 The Devil's Lake drift appears to lie on the western edge of the Ket- 

 tle Kange, no marked development of which is to be seen on top of 

 the bluff for two miles east, when knolls of limestone, pebbles, and 

 erratics of large size, are met with at the greatest elevations. 



Northward from Devil's Lake the Eange traverses the Baraboo 

 valley — in which large heaps of unmodified drift occur near the vil- 

 lage of the same name — and passing thence through northern Sauk 

 county, crosses the Wisconsin into northwestern Columbia (Newport 

 und Lewiston), and southeastern Adams. Here begins the great de- 

 velopment of kettles, both dry and lake-filled, which is continued 

 northward — the width of the whole range at the same time greatly 

 expanding — through northwestern and northern Marquette, Wau- 

 shara, eastern Portage, and western Waupaca counties, to the line of 

 the Wisconsin Central railroad, and for an indefinite distance in the 

 less settled and unsettled regions beyond. In Waushara county, the 

 Range has attained a width of fully five and twenty miles, the kettles, 

 lakes, knolls and ridges lying thickly spread over the whole surface. 

 As instances of finely marked kettles, may be mentioned those that 

 occur very numerously over the town of Springfield, Marquette 

 county, and in the eastern part of Lincoln, Adams county. These 

 are for the most part dry, often quite perfectly circular, 50 feet in 

 depth and 500 feet in width at top. They occur quite up to the edge 

 of the driftless area, and within a mile of one of the fragile sandstone 

 towers of that district — Pilot Knob. The elevation above Lake; 

 Michigan is 550 feet. Excellent illlustrations of lake-filled kettles 

 are to be found in the very numerous lakes of the towns of Marion, 

 Mount Morris, and Springwater, Waushara county. Some of these 

 are of quite large size, as, for instance, Silver lake, near Wautoma, 

 which is over a mile in length. They lie quite often in deep depres- 

 sions, the water level not unfrequently standing at 25 to 40 feet below 

 the top of the banks, which are wholly of gravel, and very steep, in 

 some cases almost perpendicular. Two or more lakes commonly 

 occur close together, the bank between them having a width on top 

 scarcely enough for a wagon road, and a steep descent to the watei 

 on either side. This is finely shovvm in the case of Silver Lake, al- 

 ready cited, and the nearly as large and partly peat-filled lake imme- 

 diately north of it. The average elevation of the country in which 

 all of these lakes lie is about 400 feet, and the country between them 

 is everywhere pitted with smaller dry kettles. 



Further west, in Waushara county, in the towns of Coloma, Rich- 



