Part 4

" various positions of 51

Faults or dykes 52

Granite 53

Gneiss 54

Strata, primary 54

Earth, primary period of 55

Stalagmites, formation of 58

Terebratula 58

Secondary system 59

Trilobites 59

Mountains, formation of 61

Earth, section of part of 62

Volcanoes, formation of 62

Coral polypi 64

Encrinites 65

Mountain limestone 65

Basalt 66

Tree-ferns, Pines, &c. 66

Air, purification of 67

Coal, formation of 67

" consumption of 68

Coal shales, ferns found in 69

Earth's surface, alterations of 69

Labyrinthodon 70

Red Sandstone, impressions in 70

Saliferous system 71

Lias and oolite 71

Ammonites and pentacrinites 72