UNIFORMITAEIANISM. 107 



period, or of the great continental movements which have interfered with 

 the continued development even of man himself. It is especially with 

 reference to these that Prestwich truly says that — 



"The forms of erosion, the modes of sedimentation and the methods of motion 

 are the same in kind as they have ever been, but we can never admit that they 

 have always been the same in degree. The physical laws are permanent ; but the 

 effects are conditional and changing, in accordance with the conditions under which 

 the law is exhibited." 



I fear that the unreasonable uniformitarianism of certain modern 

 schools of geology is a product less of scientific observation and induc- 

 tion than of the influence of certain philosophical dogmas. Lyell, the 

 great author of rational uniformitarianism in geology, well understood 

 the fact that catastrophe and cataclysm have their place in the grand 

 uniformity of nature, and that long continued uniformities must lead to 

 critical periods. He was not an agnostic or a believer in a necessitarian 

 evolution. He saw in nature adaptations and a grand plan of develop- 

 ment, including all changes, whether sudden or gradual ; and I may add 

 that it was this which gave that charm and fascination to his teaching, 

 which caused one of his contemporaries to compare the interest of the 

 Principles of Geology to that of an exciting romance. Dead material- 

 istic uniformitarianism, should 'it ever become the universal doctrine of 

 science, would provoke a reaction in the human mind which would be 

 itself a cataclysm. 



Coal-making. 



Of all the accumulations formed in geologic time probably the most 

 slowly produced are those of organic materials ; yet, curiously enough, 

 even in the present exaggerated uniformitarianism there has been a 

 endency here to return to exploded catastrophism. One can imagine 

 some of those great beds of sandstone which occur in the Coal Measures, 

 filled with trunks of trees piled in the most confused manner, to have 

 been deposited by violent inundations ; but when, after all that has been 

 done to explain the origin of coal, we find some late writers returning to 

 the old and exploded idea of the production of coal by driftage, we are 

 tempted on the one hand to vexation, and on the other to laughter. In 

 a very recent article in a well known journal I find in support of this 

 theory the contention that underclays are not ancient soils, and the fol- 

 lowing sentences, alleged to be contradictory to each other, quoted from 

 authorities on the sul)ject. The first is as follows : " Underclays are old 

 vegetable soils, and they were formed, not under water, but on dry land." 

 Now underclays are certainly vegetable soils, but they were not neces- 



