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Tue Work Dont sy Norma Brook 1N THIRTEEN YEARS. 
By Cnaries R. Dryer and MELVIN K. DAVIS. 
A small stream which enters the Wabash yalley three miles east of 
Terre Haute attracted the attention of the senior author of this paper many 
years ago by its remarkable meanders. Within a length of 1,000 feet it 
presents most of the phenomena characteristic of the lower Mississippi, 
and it has been visited so often by geography and geology classes from the 
Normal school that it has acquired the name of Normal brook. 
The stream rises by two principal forks which drain about a square 
mile of Illinoian glacial Gay plain, cuts through the east bluff of the 
Wabash valley and is lost upon the great gravel terrace below, by percola- 
tion and evaporation. Along the edge of the bluff the clay overlaid by a 
belt of sand dunes about half a mile wide, and the most interesting part 
of the stream, is that where it passes through the dune belt. A hasty 
survey of this part of the valley was wade in iS97T and a map of it was 
published in the Inland Educator for June, 1898S. During the past season 
(1910) a second and mere careful survey has been made and a comparison 
of the two maps shows the changes which have taken place in thirteen 
years. (See Figs. 1 and 2.) 
The part of the valley shown measures along the median line 1,150 
feet, while the stream, by its meanders measures 1,960 feet, an excess of 
6S per cent. In the upper 650 feet of the valley the length of the stream 
is 1,360 feet, an excess of 109 per cent. The valley floor, 100 to 200 feet 
wide, is flat flood plain bounded by bluffs 25 to 40 feet high. The ma- 
terial exposed on the floor is wnholiy alluvial, mostly sand with occasional 
bars of fine gravel and beds of tough, blue clay. In the valley floor the 
stream has cut a chaanel 20-70 feet wide and three to six feet deep. The 
stream is perennial and in ordinary stages is a thread of clear water four 
or five feet wide and six inches to a foot deep, which is much more crooked 
than the channel. In times of flood it fills the channel, but has never, in 
seventeen years of observation, overflowed the valley floor. 
Sharp zigzags, oxbow bends, cut-offs, caving banks on the outside and 
bars on the inside of the bends are numerous. 
