446 NINETEENTH CENTURY. PT. IIL 



are washed into caves, or preserved in peat-mosses; thus 

 affording us examples of the way in which the remains of 

 ancient animals have become entombed in the earth's crust. 



Thus Sir Charles Lyell taught men to read the true his- 

 toiy of the earth. It is difficult in the present day to under- 

 stand rightly how great a work he accomplished, for though 

 his ideas were ridiculed in the beginning, yet he lived long 

 enough to see all men agree with him, and his doctrines 

 received as evident truths. Like all other great men, he 

 was humble and reverent in his study of nature. His 

 one great desire was to arrive at truth, and by his con- 

 scientious and dispassionate writings he did much to per- 

 suade people to study geology calmly and wisely, instead 

 of mixing it up with angry disputes, like those which, in 

 the time of Galileo, disfigured astronomy. He travelled 

 a great deal, especially in America, and worked out a great 

 many facts in geology. But in future ages his name will 

 stand out among those of other geologists chiefly as having 

 shown that the changes in the crust of our earth have been 

 brought about in the course of long ages by causes like those 

 which are still in action. 



After the year 1830, when his 'Principles of Geology' 

 was first published, the study of this science went on very 

 lapidly indeed. A few years before, Sir Roderick Murchison 

 (1792-1871) and Professor Sedgwick (17 87-1 873) had begun 

 to map out the early formations in Wales with the same 

 accuracy that William Smith had employed in England, and 

 from this time Murchison continued for many years to un- 

 fold the history of the Silurian rocks in Wales and England, 

 the Permian rocks in Russia and the 'Fundamental gneiss* 

 or earliest known rocks in Scotland. On the Continent also 

 and in America, surveys began to be established to map out 

 the ground and ascertain the position and age of the various 



