682 J. A. TDDEX COMPOSITIOX OF CLASTIC SEDIMENTS 



235. Dune sand, Alliance, Nebraska. 



236. Front slope of dune, Alliance, Nebraska. 



237. From a coarse layer In dune sand, Hyannis, Nebraska. 



238. From a fine seam in dune sand, Hyannis, Nebraska. 



239. From the rear slope of a small dune near Moline, Illinois. 



240. From the top of a small dune near Moline, Illinois. 



241. From the top of a small dune near Moline, Illinois. 



242. From the lower front slope of a small dune near Moline, lUiQois. 



243. I'rom the top of a dune near Moline, Illinois. 



244. From the upper front slope of a small dune, Moliae. Illinois. 



245. From the top of a small dune, Moline, Illinois. 



246. From the lower front slope of a small dune, Moline, Illinois. 



247. From a dune east of Carman, Illinois. 



248. Blown field, Decorra, Illinois. 



Incipiently Moiiii sand. — Some specimens of sand were collected from 

 widely distant places, where the wind has just begun to work on materials 

 of quite diversified composition. In the following table one sample was 

 collected in Kansas in a bottle placed about a foot above the ground in 

 a drifting cultivated field, where the soil held gravel as well as clay ; one 

 was taken from the surface of a snow-drift in Maryland, where the de- 

 posit had blown from an exposure of Potomac sand of somewhat hetero- 

 geneous composition ; one is from a gutter in the city of Baltimore, and 

 was sifted out by the wind from the dust on a paved street ; one is from 

 the beach at Saint Augustine, in Florida, where such sand is reported to 

 be tossed about by the sporting wind with particular ease, owing to the 

 fact that the water has already effected a most favorable sorting, and 

 one was collected in a small receptacle placed on a drifting railroad bed 

 in the west part of Illinois. The chief ingredient in these sands is alike 

 in all and is of the same grade as that found in dune sand. 



List of Samples in TaMe 24 



249. Incipiently blown sand, Lindsborg. Kansas. 



250. Sand blown on a snow-drift. Baltimore. Maryland. 



251. Sand blown in a gutter, Baltimore, Maryland. 



252. Sand blown on the beach, St. Augustine, Ilorida. 



253. Blown sand on a railroad bed. Carman, Illinois. 



Lee sand. — In front of a dune drift and confluent with it there is gen- 

 erally a rippleless bench of sand, which has settled in the eddy in the lee 

 of the larger drift.^ The sand in the lee drift, as it may be called, is 

 found to be a little finer than the dune sand proper. Its grains have 



^ Johannes Walther : Die Denudation in der Wiiste, etcetera, p. 172, fig. 89. First 

 edition. 



