6 THE STORY OF THE LIVING MACHINE. 



for, then at once was created a new department of 

 thought and a new science inaugurated. 



Historical Geology. Preparation had been made 

 for this new method of studying life by the for- 

 mulation of a number of important scientific dis- 

 coveries. Prominent among these stood historical 

 geology. That the earth had left a record of her 

 history in the rocks in language plain enough to 

 be read appears to have been impressed upon 

 scientists in the last of the century. That the 

 earth has had a history and that man could read 

 it became more and more thoroughly understood 

 as the first decades of this century passed. The 

 reading of that history proved a somewhat diffi- 

 cult task. It was written in a strange language, 

 and it required many years to discover the key 

 to the record. But under the influence of the 

 writings of Lyell, just before the middle of the 

 century, it began to appear that the key to this lan- 

 guage is to be found by simply opening the eyes 

 and observing what is going on around us to-day. 

 A more extraordinary and more important discov- 

 ery has hardly ever been made, for it contained 

 the foundation of nearly all scientific discoveries 

 which have been made since. This discovery pro- 

 claimed that an application of the forces still at 

 work to-day on the earth's surface, but continued 

 throughout long ages, will furnish the interpreta- 

 tion of the history written in the rocks, and thus 

 an explanation of the history of the earth itself. 

 The slow elevation of the earth's crust, such as is 

 still going on to-day, would, if continued, produce 

 mountains ; and the washing away of the land by 

 rains and floods, such as we see all around us, 

 would, if continued through the long centuries, 

 produce the valleys and gorges which so astound 



