368 THE RELATIONS OF GEOLOGY. 



existence of man upon the earth for more than a few thousands of years. 

 And among the g('ok)oists of the precedino- generation the demand of 

 the so-called ''uniforinitarians'" for those vast ieons which must be 

 granted if the geological formations were accumulated and deposited 

 at the same rate as corresponding accimmlations are Ijrought together 

 at the present day, was only reluctanth" 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 sug- 

 gest a geological antiquity for our glo))e of more than a few millions of 

 ■j^ears. 



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

 tlieii- drafts upon the bank of time; but nothing whatever is gained, 

 and very much is lost, l>y persistent niggardliness in this direction. 

 The astronomer, although persuaded of the possible inrinity of the 

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

 base lines of millions of miles as is the geographical survej^or who 

 takes years, it may be, to measure accuratel}" the length of a base line 

 a few miles in extent l)efore he commences the triangulation of a single 

 country. But the consciousness of the astronomer of the practical 

 inlinity of his realms gives him a freedom of action in dealing with 

 space which is delightful. In the same wa}^ the geologist, who is })lest 

 with an assured conviction of the immensity of geological time, moves 

 with an ease and freedom from cause to effect wholl}- denied to those 

 wanting in this conviction. No doctrine in geology has resulted in 

 such ])rilliance of discovery as the doctrine of uniformitarianisn), 

 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 pos- 

 sible, but absolutely demonstrates T)}" discovery after discover}^ the 

 true extent of the ieons that have gone to the making of the geological 

 formations, he is cc^rtain to foster and eventually to establish in the 

 minds of men a fidl and adequate conception of the immensity of geo- 

 logical time. 



GEOLOCY IN PARTICULAR. 



I have said that the widest definition of geology is that it is that 

 science which, leaving to astronomy the stud}' of the heavenly bodies 

 as a society, devotes itself to the study of the earth as an individual; 

 in other words, that it is a "geonomy" as contrasted with an 

 "astronomy." But while this description is justifiable in principle, it 

 is open to the natural objection that it shares this earth-knowledge 



