26 future's /nMracles. 



time, and the opportunity that peat bogs offer 

 for an intermixture of earthy with the vege- 

 table matter. The fact that we find the im- 

 print of trees and ferns and other vegetable 

 growth of tropical varieties, as well as the fos- 

 sils of reptiles, imbedded in the coal measures, 

 proves that at one time this stratum was at 

 the land surface of the earth. We also find 

 that all of the formations of the Secondary 

 and Tertiary periods are on top of the coal 

 and this shows that after the age of rank 

 vegetable growth there was a sinking of the 

 earth in many places far down into the ocean 

 so that vast layers of rock formed on top 

 of these beds of vegetable matter. In Eng- 

 land great chalk beds crop out in cliffs on the 

 southern coast, and, as we have seen, these 

 chalk rocks are largely made up of the shells 

 of marine animals. London stands on a chalk 

 bed, from six hundred to eight hundred feet 

 thick. Indeed, England has been poetically 

 called Albion, White-land, from this appear- 

 ance of her coast. 



All of the great chalk beds were formed 

 ages after the coal beds, as the latter are 

 found in the upper strata of the Paleozoic 

 period. 



A study of these strata will show that there 

 are many layers of coal strata varying in 

 thickness and separated by layers of shale and 

 sandstone. How the shale and sandstone 



