920 THE JOURNAL OF GEOLOGY. 
Experiment 2—A box 3 inches high by 3 inches wide was 
furnished with an escarpment 54 inch high. The wax was pro- 
vided with a basal layer of darkened wax ¥% inch thick. It was 
shoved 7 or 8 inches. Fig. 2. 
Fic. 2. 
Experiment 3—The same box as in Experiment 2 was pro- 
vided with an escarpment 1 inch high and the wax provided with 
a thicker basal layer of darkened wax. The same length of 
shove was given. Fig. 3. 
Fic. 3. 
Experiment 4—A box 3% inches wide and 6 inches high with 
an escarpment 7 inch high. The wax was provided with a 
basal layer of darkened wax and a little light wax, 34 inch, was 
packed between it and the escarpment. It was shoved about 13 
inches. Fig. 4a. 
Experiment 5.—The box used in Experiment 4 was provided 
with an obstruction 7% inch high and 24% long with an abrupt 
front and gently sloping rear. The wax was furnished with a 
basal layer of darkened wax and shoved about 10 inches. Fig. 
46. 
Experiment 6.—A box 3% by 6 inches with an escarpment 1% 
inches high. The wax was provided with a basal layer of dark- 
