228 THE ILLINOIS GLACIAL LOBE. 



ridge there are scattering knolls surrounded by very level tracts. One 

 knoll near the line of sees. 1 and 2, Raymond Township, covers not less 

 than 10 acres and has a height of probably 30 feet. Other knolls 10 to 25 

 feet in height were observed. The Middle Ridge does not connect closely 

 with the Outer Ridge in southeastern Champaign and southwestern Ver- 

 milion counties, but is separated from it by a sag or depressed tract a half 

 mile or less in width. This depression connects on the east with the Little 

 Vermilion River and on the west with the Nile, a tributary of Embarras 

 River. 



For about 5 miles eastward from the Palermo geodetic station a single 

 broad ridge, 1J to 2 miles wide, constitutes the equivalent or continuation 

 of the two ridges found farther west. It does not long continue the sole 

 representative, however, for another ridge sets in just north of the head- 

 waters of Bruillett's Creek, in sec. 4, T. 16, R. 12 W. From this section 

 eastward nearly to the State line there is a double ridge, the members of 

 which are nowhere separated more than one-half mile. Mortimer stands on 

 the outer and Ridge Farm village on the inner of these ridges. A few basins 

 occur along the ridges in southeastern Vermilion County, the deepest of 

 which are depressed 8 or 10 feet below bordering land and are occupied by 

 peat bogs. The ridges have gentle undulations of 10 to 20 feet, both along 

 the crest and on the slopes. The Outer Ridge has interruptions or gaps 

 which afford a passage for waters which fall between the two ridges south- 

 ward to the outer-border plain. The gap through which Bruillett's Creek 

 passes is nearly 75 feet in depth and less than one-half mile in width. Sev- 

 eral other gaps of less depth occur, all of which are quite narrow. They 

 appear to have been deepened considerably by the streams which pass 

 through them. The two ridges become coalesced at Pilot Grove, a promi- 

 nent point in sec. 33, T. 17, R. 11 W. From this grove eastward to the 

 State line, knolls and ridges rise from the crest and slope somewhat abruptly 

 to heights of 15 or 20 feet, and give the moraine a sharper expression than 

 is usually displayed. From the State line eastward to the Wabash River 

 the bulk as well as the expression, decreases, the crest becomes poorly 

 defined, and the undulations are scarcely 10 feet in height. 



For a few miles east of the Wabash River the moraine is represented 

 by knolls only, there being no well-dehned ridge or crest line. The most 

 prominent knolls observed are in sec. 17, Reserve Township, Parke County. 



