WASTE AND RECONSTRUCTION. 



THE EARTH'S CRUST SUBJECT TO INCESSANT WASTE AND RECON- 

 STRUCTIONSLOW 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-CURRENTS 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 RECON- 

 STRUCTION THESE ENDURING AS THE PLANETARY SYSTEM. 



" OUR solid earth is everywhere wasted, where exposed to 

 the day. The summits of the mountains are necessarily 

 degraded. The solid and weighty materials of those moun- 

 tains are everywhere urged through the valleys by the force 

 of running water. The soil, which is produced in the de- 

 struction of the solid earth, is gradually travelled by the 

 moving water, but is constantly supplying vegetation with 

 its necessary aid. This travelled soil is at last deposited 

 upon the coast, where it forms most fertile countries. But 

 the billows of the ocean agitate the loose materials upon the 

 shore, and wear away the coast, with the endless repetitions 

 of this act of power, or this imparted force. Thus the con- 

 tinent of our earth, sapped to its foundation, is carried 

 away into the deep and sunk again at the bottom of the 

 sea, whence it had originated, and from which, sooner or 

 later, it will again make its appearance. We are thus led 

 to see a circulation in the matter of this globe, and a system 



