4 PRINCIPLES OF GEOLOGY. 



Mr. Smith is no theorist in the ordinary sense of the word. His whole 

 life has been spent in practical researches, to prove the truth, and extend 

 the benefit, of those general laws of structure which he was the first to 

 promulgate in England. Besides discovering, at nearly the same period 

 as Werner, the principle of the arrangement of secondary strata, he added 

 the important doctrine, that organic fossils are distributed in the earth 

 according to regular laws, and may be employed to discriminate and 

 identify the rocks. Werner and Smith are, therefore, the leaders of the 

 modern school of geology, and whilst every fresh investigation illustrates 

 the truth of their general principles, their names will be honoured with 

 increasing respect, though every " theory" should be forgotten. 



The methodical developement of first principles in geology, attempted 

 in the following pages, is the result of repeated reflections on the sub- 

 ject, for the purpose of public instruction. It is a condensed abstract of 

 parts of my lectures. Hoping that this account of the strata of the 

 Yorkshire coast would be read by others besides professed geologists, I 

 thought it desirable to furnish them with a plain distinct introduction 

 to the science, in order to avoid obscurity and tedious repetition. 



Formerly, the materials near the surface of the earth were thought to 

 be every where alike, just as agriculturists now speak of the vegetable 

 mould; and the internal parts were supposed to be a mere heap of 

 minerals confusedly blended together : a very little experimental inves- 

 tigation was sufficient to overthrow so groundless a notion. One dis- 

 trict has beneath the surface, chalk ; another, oolitic limestone ; a third, 

 coal ; a fourth, granite ; and these are never mixed or confounded 

 together ; so that the most careless observer finds himself constrained 

 to admit that not disorder, but method, appears in the situation of dif- 

 ferent rocks. 



A person proceeds from London to North Wales. After passing low 

 diluvial plains about London, he climbs, by a long slope, the chalk-hills 

 of Oxfordshire and Berkshire ; then crosses vales of clay and sandstone, 

 ascends a range of oolitic limestone ; traverses wide plains of blue and 



