CHAPTER XVIII 



HOW THE COAL BEDS WERE 

 LAID DOWN 



IN following the history of the rocks, we shall have 

 presently to speak of that period which embraces the 

 strata which contain coal. The geologists who 

 lived in the early part of last century William Smith 

 and others noticed that beneath the coal-bearing strata 

 there lay a considerable thickness of red sandy beds 

 containing the remains of fresh-water fishes, shells, and 

 plants, while above the coaly strata they found another 

 thick mass of red sandstone. To the lower and older red 

 rocks they consequently gave the name of OLD RED SAND- 

 STONE, and to the upper and newer ones the name of the 

 NEW RED SANDSTONE. The Old Red Sandstone formation, 

 therefore, lies between the Silurian rocks below and the 

 rocks of the coal period above. But in Devonshire we 

 find a considerable thickness of shales, slates, and lime- 

 stones containing marine fossils, and these also lie between 

 these two formations, and must therefore be somewhere 

 about the same period, or geological age, as the Old Red 

 Sandstone. The name "Devonian" has therefore been 

 given to these shales, slates, and limestones, which 



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