en. XL. GEOLOGY. 44 i 



CHAPTER XL, 



SCIENCE OF THE NINETEENTH CENTURY (CONTINUED). 



Prejudices which retarded the Study of Geology Lyell, ' Principles of 

 Geology' Murchison Louis Agassiz Glacial Period MacEnery 

 Boucher de Perthes Flint Implements ' Antiquity of Man ' 

 Swiss Lake-dwellings Study of Petrology. 



IN 1811, when Cuvier published his work on 'Fossil Re- 

 mains,' William Smith, who, as you remember (p. 221), first 

 studied the rocks of England, had nearly completed his geo- 

 logical map, and scientific men were beginning, both in 

 England and Germany, to understand something of the dif- 

 ferent ages of the formations which have been laid down 

 from time to time on the surface of the globe ; yet still they 

 were prevented from reading the past history of the world 

 rightly, by several false notions which continued to prevail. 

 People had so long held the belief that our earth had 

 only existed a few thousand years, that when geologists 

 began to find great numbers of strange plants and animals 

 buried in the earth's crust, immense thicknesses of rock laid 

 down by water, and whole mountain-masses which must 

 have been poured out by volcanoes, they could not believe 

 that this had been done gradually and only in parts of the 

 world at a time, as the Nile and the Ganges are now carry- 

 ing down earth to the sea, and Vesuvius, Etna, and Hecla 

 are pouring out lava a few feet thick every year. They still 

 imagined that in past ages there must have been mighty 



