VAST INTERVALS OF TIME. 257 



is based, that since the deposition of the rubbish-cones of Clarens, 

 near the Lake of Geneva, which belong to the end of the drift 

 period, at least 100,000 years have elapsed, yet numerous phe- 

 nomena indicate the lapse of many thousands of years. 



It has been already noticed (p. 199) that the drift period 

 must have continued for an enormous time, which is shown 

 by the increase and retirement of the glaciers, the disper- 

 sion of erratic blocks over the lowlands, the formation of beds 

 of rivers, and the distribution of plants and animals. These 

 varied and remarkable phenomena certainly required an ex- 

 cessively long lapse of time ; and going back to their com- 

 mencement we arrive at the Tertiary period. Through the 

 stormy epoch which gave to the Swiss Alps their present ex- 

 ternal configuration, we reach the Miocene period. Let us 

 consider all that took place during the Middle Tertiary epoch, 

 from the marine Miocene of Basle to the (Eningian formation 

 all the oscillations in the level of the ground, and all the changes 

 in the nature of the land and we shall be obliged to admit 

 that such transformations could be effected only in the course 

 of many thousands of years. And yet we are still upon soil on 

 which the world of waters in general had nearly the same cha- 

 racter as at present. But if we look further back to the Flysch 

 and Nummulitic formations, to the Cretaceous period and the 

 Jurassic sea, to the Trias and the Carboniferous deposits, and 

 the older Palaeozoic rocks, and to those primaeval periods when 

 the earth was still desert and void, one strange picture succeeds 

 another, somewhat as in the heavens star starts forth beyond 

 star in immeasurable distances, until we give up the task of 

 calculating the number of years which may express those periods 

 of time. But although time and space may be compared to a 

 shoreless ocean, the spheres of the universe which move in that 

 ethereal sea are nevertheless finite magnitudes ; and as the dis- 

 tances of the nearest stars can be measured, the human intellect 

 will perhaps some day discover the means of determining the 

 distances of time which separate the different phases of the de- 

 velopment of our planet. At present, however, the duration of 

 these vast periods is not known ; and when we speak of a thou- 

 sand millions and of ten thousand millions of years as required 

 for one among many geological formations, we do not consider 



VOL. II. s 



