160 THE OLD COAL-MEASUKES. 



" Old Eed/ J and the latter the " New Eed," by the sys- 

 tematic geologist. It thus holds a sort of middle place in 

 chronological classification, being younger than the Cam- 

 brian, Silurian, and Old Red systems, and older by far 

 than the Chalks, Oolites, and New Eed Sandstones. Its 

 position is well defined, and may be seen at a glance in the 

 following sequential arrangement : 



CAINOZOIC , ( Quaternary or Recent. 

 (Recent). \ Tertiary. 



( Cretaceous or Chalk. 

 flf^/T 1 Oolitic or Jurassic. 



t Triassic-(Upper New Eed). 



{Permian (Lower New Eed). 

 CARBONIFEROUS THE OLD COAL-MEASURES. 

 Old Eed Sandstone and Devonian. 

 Silurian. 



Eozoic ( Cambrian. 



(Dawn.) \ Laurentian. 



It is to these paleozoic or ancient coal-measures, in con- 

 tradistinction to all others, that we direct the present 

 sketch, dwelling more especially on their geological aspects, 

 and only incidentally alluding to their industrial applica- 

 tions and importance. We say " incidentally alluding ; " 

 for their building-stones, fire-clays, alum-shales, limestones, 

 ironstones, and coals the labour and skill expended in 

 mining them, the innumerable uses to which they are ap- 

 plied, and their bearings on the industrial and social condi- 

 tions of a people are subjects which of themselves would 

 require the consideration of half-a-dozen sketches. 



Perhaps the most intelligible way of treating any geolo- 

 gical system, is to consider it first as a Eock-formation, 

 second as a Life-period, and third as an Economic reposi- 

 tory. In this way we get an insight into the nature of the 

 strata of which it is composed, and the agencies concerned 



