GEOLOGY OF DERBYSHIRE. 227 



find the gritstones become more numerous and thicker, until they 

 assume the appearance of a mass of gritstones, between certain beds 

 of which occurs sometimes a bed of shale containing a thin bed of 

 coal. To this mass of gritstones is applied the term of 



7- — The Millstone Grit. 



This name of the millstone grit, (the derivation of which is suffi- 

 ciently obvious), is applied by the Derbyshire coal and iron owners 

 solely to the lowest bed of grit in the district, which is certainly 

 the thickest and most important ; and this is the sense in which the 

 word is used by Farey, and in which it must continue locally to be 

 received. There are, however, several beds of grit above this, 

 which cannot be distinguished from it by any character except that 

 of position, and which unite with it to form the remarkable and 

 decided country of the Moorlands. These beds taken together consti- 

 tute a well-marked division of the series, having peculiar features 

 both as to the kind of country it composes and its other characters, 

 which would be left without any common designation unless that 

 of the millstone grit be extended to it. This extension accords both 

 with the system of nomenclature adopted by geologists and with 

 actual fact, since millstones are got from all these beds of gritstone 

 indiscriminately. As far as I have seen of the country, I should 

 think that the four first gritstones of Farey (ht reckons from the 

 bottom) would enter into this group ; and the millstone grit would 

 then consist of 



1. Gritstone 



2. Shale with a bed of coal 



3. Gritstone 



4. Shale with a poor band of coal 



5. Gritstone 



6. Shale with a coal smut 



7. Gritstone, called by Farey first or millstone grit.* 



We thus get a peculiar and important group clearly marked out, 

 and give to this division of the series a greater equality with the 

 others ; and we render more intelligible the occurrence of several 



" Coal and shale occur both in the millstone grit of Yorkshire and below 

 it : we shall then by this plan have the group consistent throughout, and it 



Is the nomenclature always adopted by geologists See Phillip's Geologv, in 



Lordlier*! Cabinet Cyclopcedia, Vol. I, p. i,v>. 



