NO.6 — Experiments illustrating Erosion and Sedimentation. 
By Tuomas AUGUSTUS JAGGAR, JR. 
CONTENTS. 
PAGE, 
BEOUCCTON ee ME BERR A RN 
Catchment basins and Water-béaring strata. ae, 0 a SD 
tivo character of rilsa i UPA en "296 
Purpose ohexporimente bit Miles do Pao: 986 
Previous studies of rill drainage Harani O DR OST 
The Laboratory of Experimental Geology (Harvard University): pre- 
Iwan experimente ade. di. ptos a da SE 
ee A IA ee a RT 
Underground drainage areas and stream shadow... . . . =; 289 
re i ge Ok Ge ey ee 
“Grand Canyon model = 2 ay una, OU 
a De TR 
Mel sprayed wichiatomizerse ne ee O 
Stream-robbery Ode. Se oe ek II A ee 299 
Di cussionof principles: deko; eis Aime realer er Be 
Bibliography . . . ee! Se ee 0A 
Alina tomo plates. abria oeaio laannan 81.1805 
Inrropuction. The fundamental conceptions of river develop- 
Ment in current physical geography are as follows:— (1) young rivers 
Cut down their channels where the slope is steep enough to give them 
an active current, but where the slope is faint, the streams lay down 
their load of detritus and build up the surface. (2) A branch stream 
of a larger river has the advantage of the greater depth to which the 
Main valley is worn. In competition with like branches of smaller 
Nearby rivers its divide will shift faster. This doctrine is commonly 
applied to ‘belted coastal plains.” (Davis.) 
CATCHMENT BASINS AND WATER-BEARING STRATA. It is of course 
recognized that velocity of current increases with increase of volume, 
and where two streams have like slope, the more voluminous will 
lave greater corrasive power. There are two very important ele- 
Note: — This research was carried on in the Laboratory of Experimental Geology, 
Harvard University, while the author was there a teacher of Geology, and was aided 
Y Grant 101 Elizabeth Thompson Science Fund. The author wishes to express to the 
Tustees his grateful appreciation of this grant. 
