List of Illustrations 



PAGE 



The Sella Mass, Tyrol ..... Frontispiece 

 FIG. 



1. Geothermal Map of the British Isles . 19 



2. Stages in the Formation of a Mountain Chain . . 35 



3. Europe in the Cambrian Period . . . . .42 



4. Form of the Earth subsequent to the Ejection of the Moon . 47 



5. Subsequent Deformation of the Earth . . . .49 



6. Map showing the Symmetrical Distribution of Land and Sea 53 



7. Elie de Beaumont's Pentagonal Dodecahedron Unfolded . 57 



8. Fractures in the Tyrrhenian Sea ... .67 



9. Stromboli, from the West Side of the Crater ... 73 



10. Volcano in Eruption . . ... 75 



11. A Volcanic Bomb ... 76 



12. Crater of Volcano, immediately before an Eruption . . 77 



13. First Puff of an Eruption, Vulcano .... 78 



14. The Same Eruption, a little later . . . . .79 



15. The Same Eruption, still later .... 80 



16. Final Stage of the Eruption . . . . .81 



17. Diagram to illustrate the Mechanism of a Strombolian Eruption 82 



18. Diagram to illustrate the Mechanism of a Vesuvian Eruption 84 



19. A Coral Atoll, according to Chamisso .... 90 



20. Fringing Keef , Darwin . . . . . .92 



21. Encircling Reef, Darwin .... .93 



22. Atoll, Darwin . . . . . . .94 



