118 GEOLOGICAL CHANGE, AND TIME. 



inquiry, and exercised in that respect a baneful influence on intellectual 

 progress. 



It is the special glory of the Edinburgh school of geology to have 

 cast aside all this fanciful trifling. Huttou boldly proclaimed that it 

 was no ])art of his philosophy to account for the beginning of things. 

 His concern lay only with the evidence furnished by the earth itself as 

 to its origin. With the intuition of true genius he early jjerceived that 

 the only solid basis from which to exj)lore what has taken place in 

 bygone time is a kno^^ ledge of what is taking place to-day. He thus 

 founded his system upon a careful study of the processes whereby geo- 

 logical changes are now brought about. He felt assured that Nature 

 must be consistent and uniform in her working, and that only in pro- 

 portion as her operations at the present time are watched and under- 

 stood will tlie ancient history of the earth become intelligible. Thus, 

 in his hands, the investigation of the Present became the key to the 

 interpretation of tlie Past. The establislnnent of this great truth was 

 the first step towards the inauguration of a true science of the earth. 

 The doctrine of the uniformity of causation in Nature became the 

 fruitful principle on which the structure of modern geology could be 

 built up. 



Fresh life was now breathed into the study of the earth. A new 

 spirit seemed to animate the advance along every i^athway of inquiry. 

 Facts that had long been familiar came to possess a wider and deeper 

 meaning when their connection with each other was recognized as parts 

 of one great harmonious system of continuous change. In no depart- 

 ment of Nature, for exam})le, was this broader vision more remarkably 

 displayed than in that wherein the circulation of water between land 

 and sea plays the most conspicuous part. From the earliest times men 

 had watched the coming of clouds, the fall of rain, the flow of rivers, 

 and had recognized tliat on this nicely adjusted machinery the beiiuty 

 and fertility of the land depend. But they now learned that this 

 beauty and fertility involve a continual decay of the terrestrial surface; 

 that the soil is a ]neasure of this decay, and would cease to afford us 

 maintenance were it not continually removed and renewed; that 

 through the ceaseless transi^ort of soil by rivers to the sea the face of 

 the land is slowly lowered in level and carved into mountain and valley, 

 and that the materials thus borne outwards to the floor of the ocean 

 are not lost, but accumulate there to form rocks, which in the end vcill 

 be upraised into new lands. Decay and renovation, in well-balanced 

 proportions, were thus sliown to be the system on which the existence 

 of the earth as a habitable globe had been established. It was impos- 

 sible to conceive that the economy of the planet couUl be maintained 

 on any other basis. Without the circulation of water the life of plants 

 and animals would be impossible, and with that circulation the decay 

 of the surface of the land and the renovation of its disintegrated mate- 

 rials are necessarily involved. 



