CONTENTS. 



Page 

 PRELIMINARY OBSERVATIONS,, ------ ^g^ib,! 



Plan of the Essay, - - - : im/^whi^/'f-etl* gffrt -jerjwn - 4 

 First Appearance of the Earth, -c, rf j -^Mmi,** - - - 6 

 First Proofs of Revolutions on the Surface of the Globe, - 6 

 Proofs that such Revolutions have been numerous, - - 10 

 Proofs that these Revolutions have been sudden, - - - 14 

 Proofs of the Occurrence of Revolutions before the Exist- 

 ence of Living Beings, ---------16 



Examination of the Causes which act at present on the 



Surface of the Globe, . if .*n^ 4 _%" ,- 23 



Of Slips, or Falling Down of the Materials of Mountains, 25 

 Of Alluvial Formations, >>*W*ia!*MKft -T& im: J* - - 26 

 Of the Formation of Downs, ---------28 



Of the Formation of Cliffs, or Steep Shores, '8 'few- - - 29 

 Depositions formed in Water, - - - - - - . ^ .4i ;, 30 



Of Stalactites, 31 



Of Lithophytes, - - - -^torfMtt* .r.&fpita4. ***** - - 32 

 Of Incrustations, ----..----. -32 



Of Volcanoes, ;amc*K - 34 



Constant Astronomical Causes, --------36 



Older Systems of Geologists, 38 



