4. Ripple marks, mud cracks, etc. 
5. Stalactites, stalagmites and other cave pro¬ 
ducts. 
6. Gypsum cave. 
7. Faults, joints, etc. 
8. Pebbles. 
9. Sedimentary rocks. 
10. Metamorphic rocks. 
11. Igneous rocks. 
12. Relief Maps. 
a. Hawaiian Islands and other volcanic islands. 
b. Porto Rico. 
c. Development of Chicago Plain. 
d. Various States and Sections of United States. 
Niagara, Grand Canyon, Yosemite Valley, Illi¬ 
nois, etc. 
e. Palestine. 
f. Ancient Ice Sheet in United States. 
g. Rainfall and Temperature in United States. 
18. Model of Natural Bridge, Virginia. 
C. Hall 36. Petroleum, Coals and Clays. 
(East to West) 
1. Oil sand and rocks. 
2. Oils and oil products. 
3. Coal tar products. 
4. Asphalt. 
5. Coals. 
6. Oil shales. 
7. Graphite. 
8. Magnesite and Sulphur. 
9. Peat. 
10. Diamonds. 
33 
