PLATE 1. 
PLATE 2 
PLATE 
PLATE 4 
PLATE 
PLATE 
EXPLANATION OF PLATES. 
Fig. 1. Seepage streams in unstratified sand. Original 18 x 24 
inches (.457 X .609 m). 
Fig. 2. Seepage stream in stratified sand. Original 18 inches 
(.457 m) delta front to head of stream. 
Arborescent drainage formed by sudden flood run-off. 
Stone’s “Grand Canyon” model. Original 48 inches (1.22 m) long. 
Note. Bend in lower bands is apparent, not real, and is due to 
the perspective of a curved surface in section. ` 
Arborescent triekle-pattern formed by tilting a surface covered 
with liquid clay. Tilt 45% Actual size. 
Fig. 1. Slime model, first stage. Sprayed with atomizers. Origi- 
nal 63 X 8% inches (.165x.216 m). 
Fig. 2. Slime model, second stage. 
Slime model illustrating stream capture. 
