404 TBANS ACTIONS OP SECTION C. 



These somewhat exceptional manifestations come well within our conceptions of 

 uniformity, and many of us have felt with Lyell ' ' that the energy of the sub- 

 terranean movements has been always uniform as regards the whole earth. 

 The force of earthquakes may for a cycle of years have been invariably confined, 

 as it is now, to large but determinate spaces, and may then have gradually 

 shifted its position, so that another region, which had for' ages been at rest, 

 became in its turn the grand theatre of action.' 



James Hutton has sometimes been charged with catastrophic tendencies, in 

 requiring a complete wearing away of the continents, followed by a somewhat 

 sudden restoration of the land-surface. But he was careful to urge ^ that ' the 

 powers of Nature are not to be employed in order to destroy the very object of 

 those powers ; we are not to make Nature act in violation to that order which 

 we actually observe.' To him, the object of the earth's existence was the 

 propagation of life, and particularly of man, upon its surface. We must 

 presume that the destructive outpourings of the lava-rifts of Laki in 1783 and 

 the human hecatomb on the quay at Lisbon in 1755 had not appealed to him as 

 breaks in an orderly succession. He admits ' that ' this world is thus destroyed 

 in one part, but it is renewed in another; and the operations by which this 

 world is thus constantly renewed are as evident to the scientific eye as are those 

 in which it is necessarily destroyed.' Yet the operations that are to ' give birth 

 to future continents,' as well as those that wear down a continent to the level of 

 the sea, are not the result of ' any violent exertion of power, such as is required 

 in order to produce a great event in little time ; in nature, we find no deficiency 

 in respect of time, nor any limitation with regard to power.' ■* Far from 

 believing in the complete loss of the former land-surface before upheaval raised 

 the new, Hutton points out that ' the just view is this, that when the former 

 land of the globe had been complete, so as to begin to waste and be impaired 

 by the encroachment of the sea, the present land began to appear above the 

 surface of the ocean. In this manner we suppose a due proportion to be always 

 preserved of land and water upon the surface of the globe, for the purpose of a 

 habitable world, such as this which we possess.' He then observes that the 

 materials brought to light from the bottom of the sea must have been derived 

 from a land-surface still older than that which is decaying simultaneously with 

 the uprise of new continents. Though he speaks of the strata formed at the 

 bottom of the sea as becoming ' violently bended, broken, and removed from 

 their original place,' he refrains from definite assertions as to the details of the 

 process of elevation.' Fusion, whereby original rock-structures are lost, sub- 

 sequent consolidation, and final upheaval by thermal expansion, seemed to 

 Hutton the broad stages of that part of his cycle which is concerned with 

 reconstruction. He certainly speaks ° of ' the greatest catastrophes which can 

 happen to the earth, that is, in being raised from the bottom of the sea, and 

 elevated to the summits of a continent, and being again sunk from its elevated 

 station to be buried under that mass of water from whence it had originally 

 come.' But the gist of his whole treatise is that the process of degradation is 

 brought about by slowly acting causes, and the ' catastrophe ' of elevation is 

 kept well out of the picture, on the ground that we are unable to follow out its 

 successive stages. 



Hutton's insistence on the recurring cycle of geological events was of 

 immense value in checking the imagination of those who revelled in the con- 

 templation of 



' Crags, knolls, and mounds, confusedly hurl'd, 

 The fragments of an earlier world.' 



Stellar observation and physical chemistry, however, have alike led us to look 

 for evolutionary processes in the globe; and it is well to ask if the conditions 

 prevalent at the present day are necessarily those of previous periods, or have 



' Prlnriples of Geology, vol. i. (1830), p. 64. 



- Theory of the Earth (1795), vol. ii. p. 547. 



' Ibid. p. 562. = Ihid. pp. 163, 164, 184, and 121, 



* Ihid. (1795), vol. i. p. 182. » Ihid. vol. ii. p. 445. 



