252 HEROES OF SCIENCE. 



surface in Wales and the lake districts, and because 

 they were upheaved the newer strata were tilted 

 and curved, and the slope is to the east. 



In February, 1798, we find as part of the intro- 

 duction to this contemplated work, an interesting 

 notice of some of the steps by which the author 

 was conducted to his general conclusions. 



"It will be readily admitted by all classes of 

 men, from the most accurate observers of nature 

 to the simplest peasant, that there is some degree 

 of regularity in the strata from whence our build- 

 ing materials are generally collected. Masons, 

 miners, and quarrymen can identify particular beds 

 of stone dug many miles apart ; indeed, every cliff 

 and quarry presents a true section of a great many 

 beds of stone, which may be found of the same 

 quality and in the same position in all or most of 

 the neighbouring cliffs and quarries. And this 

 regularity is nowhere more conspicuous than in the 

 lias quarries of Somersetshire, from whence these 

 observations first took their rise, about seven years 

 since. 



" For the stratification of stone struck me, who 

 had not been accustomed to such appearances, as 

 something very uncommon, and till I had learned 

 the technical terms of the strata, and made a 

 subterraneous journey or two, I could not conceive 

 a clear idea of what seemed so familiar to the 

 colliers ; but when these difficulties were sur- 

 mounted, and an intelligent bailiff accompanied 

 me, I was much pleased with my peregrinations 



