2 Principles of Geology. 



the lucid and attractive account of the Principles of Geology which 

 we have already named, and which, notwithstanding differences of 

 opinion on theoretical topics, will we presume, be decidedly accept- 

 able to many persons who may not have access to the original work. 

 Without committing ourselves to an agreement with the author on 

 every point, we are free to say, that we know not of any sketch, 

 comprised within the same limits, which may be studied by the gen- 

 eral reader with more advantage, and even a learned geologist will 

 find it a useful review of the outlines of his knowledge. 



Condensed view of the discoveries respecting the structure of the earth, 

 which have produced the modern practical system of Geology. 



Extracted from Phillips's Geology of Yorkshire. (1829.) 



The most extensive subject which falls within the range of human 

 acquirement, is the study of nature. To comprehend the phenome- 

 na of the material world, and to illustrate the secret laws by which 

 they are governed, requires the joint labor of many minds. To fa- 

 cilitate this investigation, nature is conceived to be divided into dis- 

 tinct sections, each of which gives title to a science. Geology is one 

 of these, and its professed object is to develope the natural history of 

 the earth. It aspires to learn the various materials of which our 

 planet is composed, and to determine the manner, and, as far as, 

 secondary causes are concerned, the means of its construction. Min- 

 eralogy, chemistry, botany, zoology, are all associated with geology ; 

 their advancement keeps pace with its progress, and every discovery 

 which rewards the cultivation of them, throws new light on the revo- 

 lutions which have visited the earth. Even the astronomer, who 

 employs himself in observing other planets and other systems, and 

 the mathematician, who determines the forms and densities of sphe- 

 roids, are fellow-laborers with the practical observer of the strata. 



If, then, so many delightful themes of human study are directly or 

 indirectly connected with the earth, there is no need to assert the 

 interest, it would hardly be possible to display all the advantage, 

 which is to be expected from the study of geology. It must be ev- 

 ident that not only our daily wants are supplied, and our comforts 

 provided, by various productions which acknowledge the earth for 

 their common parent, but that the charms of scenery, and all the love- 

 ly variety of nature, are so intimately dependent on peculiarities in 

 the structure of the earth, that no one can think uninteresting a sci- 



