UNCLE IN ENGLAND. 199 



chalk, freestone, coal, limestone, sandstone, 

 slate, and granite, succeed each other with 

 tolerable uniformity, he would soon perceive 

 that there was something like system in their 

 arrangement. And on further examination, he 

 would discover that this general scries may be 

 subdivided into several lesser series or forma- 

 tions, in which, also, considerable regularity may 

 be observed. The order, then, in which these 

 series are classed by geologists, is what I am now 

 going to explain to my little girls. 



l( The first or upper series comprehends the 

 mixed beds of sand, gravel, pebbles, and clay, 

 which are frequently found covering the great 

 chalk formation. 



" The second class includes several different 

 series more or less connected with each other : 

 the most important of them are 1st, the chalk 

 formation ; 2dly, a series of sands and clays 

 beneath the chalk ; 3dly, a series of calcareous 

 freestones, such as Portland and Bath stone ; and, 

 4thly, beds of red marl and sandstone, some- 

 times containing alabaster and rock salt. 



" The third general class comprises beds of 

 coal and the limestones and sandstones on which 

 they repose. 



" The fourth or argillaceous class of rocks is 

 characterised by their disposition to split into 

 thin lamina ; such, for example, as the common 

 roofing slate. 



