CONTENTS. 



I. THE CRUST WE DWELL UPON. 



PAGE 



NATURE OF THE EARTH'S CRUST OR SOLID EXTERIOR DIFFERS 

 FROM THE INTERIOR COMPOSED OF ROCKS AND ROCK- 

 FORMATIONS THESE THE THEMES OF GEOLOGICAL INVES- 

 TIGATION TECHNICAL MEANING OF THE TERM "ROCK"- 

 STRATIFIED AND UNSTRATIFIED ROCKS HOW AND BY 

 WHAT PROCESSES FORMED OLDER AND YOUNGER ROCKS 

 EXAMPLES OF HOW DISTINGUISHED CHRONOLOGICAL AR- 

 RANGEMENT OF ROCK-FORMATIONSEACH A CHAPTER OF 

 WORLD -HISTORY ATTRACTIVE NATURE OF THIS HISTORY 

 FACTS ARRIVED AT BY A STUDY OF THE EARTH'S CRUST 

 THEIR THEORETICAL AND PRACTICAL IMPORTANCE, . 17 



II. WASTE AND RECONSTRUCTION. 



THE EARTH'S CRUST SUBJECT TO INCESSANT WASTE AND RE-^ 

 CONSTRUCTION SLOW AND GRADUAL NATURE OF THESE 

 CHANGES CAUSES OR AGENCIES PRODUCTIVE OF CHANGE : 

 1. METEORIC OR ATMOSPHERIC RAINS, FROSTS, AND WINDS 

 2. AQUEOUS RIVERS, WAVES, TIDES, AND OCEAN-CUR- 

 RENTS 3. CHEMICAL SOLUTION AND PRECIPITATION 

 4. ORGANIC PLANT AND ANIMAL GROWTHS 5. IGNEOUS 

 VOLCANOES, EARTHQUAKES, AND CRUST - MOTIONS THE 

 CRUST HELD IN EQUILIBRIUM BETWEEN WASTE AND RE- 

 CONSTRUCTION THESE ENDURING AS THE PLANETARY 



SYSTEM, ....... 35 



