lxxii PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1903, 



than a few thousands of years. And among the geologists of the 

 preceding generation, the demand of the so-called ' unif ormitarians ' 

 for those vast seons which must be granted, if the geological forma- 

 tions were accumulated and deposited at the same rate as corre- 

 sponding accumulations are brought together at the present day, was 

 only reluctantly conceded by the majority after years of conflict and 

 denial. Even at the present time it is the habit not only of eminent 

 physicists, mathematicians, and chemists, but also of some of our 

 geological authorities, to scout all reasonings that suggest a geolo- 

 gical antiquity for our globe of more than a few millions of years. 



Far be it from me to suggest that geologists should be reckless in 

 their drafts upon the bank of Time : but nothing whatever is gained, 

 and very much is lost, by persistent niggardliness in this direction. 

 The astronomer, although persuaded of the possible infinity of the 

 universe, is just as careful in estimating the length of his grander 

 base-lines of millions of miles as is the geographical surveyor who 

 takes years, it may be, to measure accurately the length of a base- 

 line a few miles in extent before he commences the triangulation 

 of a single country. But the consciousness of the astronomer of 

 the practical infinity of his realms gives him a freedom of action 

 in dealing with space which is delightful. In the same way 

 the geologist, who is blest with an assured conviction of the 

 immensity of geological time, moves with an ease and freedom from 

 cause to effect wholly denied to those wanting in this conviction. 

 No doctrine in Geology has resulted in such brilliance of discovery 

 as the doctrine of uniformitarianism, which sets no theoretical 

 bounds either to the efficacy of present causes or to the duration of 

 past time. It is not, however, the eternity of geological time that 

 this doctrine demands, but the assumption of the vast duration of 

 the geological periods of which it has been made up. And if to 

 this assumption the geologist adds the conscientious accuracy of 

 the geodesist and astronomer, and not only takes for possible, but 

 absolutely demonstrates by discovery after discovery the true extent 

 of the aeons that have gone to the making of the geological for- 

 mations, he is certain to foster and eventually to establish in the 

 minds of men a full and adequate conception of the immensity of 

 geological time. 



Geology in Particular. — I have said that the widest definition 

 of Geology is that it is that science which, leaving to Astronomy the 

 study of the heavenly bodies as a society, devotes itself to the study 



