V 29 1907 
'The Ohio Naturalist, 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume VIII. NOVEMBER, 1907. No. 1. 
TABLE OF CONTENTS 
Moody—A ggradation and Degradation of Valleys. 191 
Morse— Contribution to the Life History of Cornns Florida. ..197 
Williamson —Addition to List of Dragonflies of Canada. 204 
Schaffner —Check List of Ohio Shrubs. 205 
Sim— The Chestnut-sided Warbler Nesting at Jefferson, Ashtabula Co., Ohio. 209 
AGGRADATION AND DEGRADATION OF VALLEYS. 
A. E. Moody. 
It is the purpose of this paper to show what a river can do 
toward filling and degrading its valley, to discuss the conditions 
favorable to such work, and to briefly describe the resulting 
land forms. The paper is based on an experiment which was 
conducted at Ohio State University during the Winter of 1907 
as a part of the work in Geology 21—a course in advanced 
physiography. 1 
A watertight box, eighteen feet long, two feet wide and six¬ 
teen inches deep, was constructed; and then with weak cement 
a mature valley was built in the box. The valley walls rose on 
the sides of the box about five inches, and in the center the 
construction was about one inch deep. Fig. 1. Spurs alter¬ 
nately entered the valley from opposite sides. Fig. 2. The 
cement covered the entire bottom of the box except about one 
and one-half feet of the lower end which was left open for a 
catchment basin, where delta formation was studied. The 
upper end of the^ cement valley was covered with a pile of fire 
clay upon which played a fine spray. 
At the lower end of the box was an elevated plug perforated 
so as to let out the water above a certain height. This outlet 
could be adjusted by changing the length of the plug, so that the 
lake of accumulated water could be given any desired depth. 
A jack screw placed under the box about thirteen feet from 
the mouth of the stream permitted regulating the slope of the 
valley. Ordinary three-quarter inch rubber hose and a garden 
nozzle connected with the city water pipes furnished the spray. 
With varying city pressure frequent adjustment of the nozzle 
was necessary to keep a fairly uniform stream. 
1 The author desires to thank Dr. Hubbard, under whom the course was taken, for 
suggestions and criticisms both in the laboratory work and in the preparation of this report. 
library 
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