XL] faologM grfbrra. 243 



clock is essentially a catastrophe ; the hammer might be 

 made to blow up a barrel of gunpowder, or turn on a 

 deluge of water ; and, by proper arrangement, the clock, 

 instead of marking the hours, might strike at all sorts of 

 irregular periods, never twice alike, in the intervals, 

 force, or number of its blows. Nevertheless, all these 

 irregular, and apparently lawless, catastrophes would be 

 the result of an absolutely uniformitarian action; and 

 we might have two schools of clock-theorists, one 

 studying the hammer and the other the pendulum. 



Still less is there any necessary antagonism between \ 

 either of these doctrines and that of Evolution, which 

 embraces all that is sound in both Catastrophism and 

 Uniformitarianism, while it rejects the arbitrary assump- 

 tions of the one and the, as arbitrary, limitations of the 

 other. Nor is the value of the doctrine of Evolution to the 

 philosophic thinker diminished by the fact that it applies 

 the same method to the living and the not-living world ; 

 and embraces, in one stupendous analogy, the growth 

 of a solar system from molecular chaos, the shaping 

 of the earth from the nebulous cubhood of its youth, 

 through innumerable changes and immeasurable ages, 

 to its present form; and the development of a living 

 being from the shapeless mass of protoplasm we term a 

 germ. 



I do not know whether Evolutionism can claim that 

 amount of currency which would entitle it to be called 

 British popular geology ; but, more or less vaguely, it is 

 assuredly present in the minds of most geologists. 



Such being the three phases of geological speculation, 

 we are now in position to inquire which of these it is 

 that Sir William Thomson calls upon us to reform in 

 the passages which I have cited. Y 



It is obviously Uniformitarianism which the dis- 



B 2 



