PHYSIOGRAPHY 



INTRODUCTION 



Definition. Physiography deals with (1) the solid part of the 

 earth, the lithosphere, (2) the liquid part of the earth, the water or 

 hydrosphere, and (3) the gaseous part of the earth, the air or atmos- 

 phere. The land, the water, and all animal and plant life are 

 affected by the atmosphere, while the water is related in many ways 

 to the land and to the life of the globe. As. to the lithosphere, 

 physiography has to do with its surface only, a surface which has 

 not always had its present form. It has been shaped and re-shaped 

 by winds, rivers, waves, and ice. Volcanic forces, too, have had 

 their part in building it up and tearing it down, and over and over 

 again the outer part of the earth has been warped and wrinkled. It 

 is this ever-changing surface which concerns man and life generally; 

 and physiography has to do chiefly with the surface of the litho- 

 sphere and with the relation of air and water to it. 



Physiography and geology are closely related. The history of 

 the earth is recorded in the rocks for the student of geology, 

 and physiography deals with the latest chapter of that history, the 

 history of the present surface. 



Physiography is also related to geography; for while geography, 

 as that term is now used, is concerned chiefly with the distribution 

 of life and human industries, rather than with the physical relations 

 of earth, air, and water, this distribution depends largely upon soil, 

 climate, and natural resources. Physiography not only takes up the 

 physical side of geography, but it also sets forth much of the latest 

 and freshest chapter of geology, a chapter which can never be fin- 

 ished so long as the world continues to change. 



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