PREFACE. 



The science of the earth as illustrated by geological 

 research, is one of the noblest outgrowths of our 

 modern intellectual life. Constituting the sum of 

 all the natural sciences in their application to the 

 history of our world, it affords a very wide and varied 

 scope for mental activity, and deals with some of the 

 grandest problems of space and time and of organic 

 existence. It invites us to be present at the origin 

 of things, and to enter into the very workshop of the 

 Creator. It has, besides, most important and intimate 

 connection with the industrial arts and with the mate- 

 rial resources at the disposal of man. Its educational 

 value, as a means of cultivating the powers of ob- 

 serving and reasoning, and of accustoming the mind 

 to deal with large and intricate questions, can scarcely 

 be overrated. 



But fully to serve these high ends, the study of 

 geology must be based on a thorough knowledge of 

 the subjects which constitute its elementary data. It 

 must be divested as far as possible of merely local 

 colouring, and of the prejudices of specialists. It 

 must be emancipated from the control of the bald 

 metaphysical speculations so rife in our time, and 



