54 



This is a greater number than is now known in the 

 district, and it is just possible that Dr. Buckland may 

 have been led into the error of multiplying the number, 

 from the same veins receiving different names at different 

 collieries ; but on the whole we may take his list as sub- 

 stantially correct. 



He treats the division as a whole, but, like the upper 

 division, it has been sub-divided into two distinct series of 

 veins, known as the (third or) New Eock, and the (fourth 

 or) Vobster series. 



There is not so distinct a line of demarkation between the 

 third and fourth series as between the two parts of the upper 

 division, but there is quite sufficient distinction to justify the 

 local classification. 



The distinction lies rather in the character of the veins and 

 in the nature of the strata between them than in the in- 

 tervention of any unproductive stratum of rock. The 

 veins of the New Rock series chiefly produce house coal, 

 they are (like the veins of the upper division) free from fire- 

 damp, and the strata intervening between them is a hard 

 compact sandstone little removed fi-om pennant. Those of the 

 Vobster series, on the contrary, produce an iron-making coal 

 of great purity ; they are probably as fiery as any in England, 

 and they are separated from each other for the most part by 

 an exceedingly tender shale. 



On the section I have dotted the probable line of separa- 

 tion between the two series, but as they merge gradually into 

 each other, it is difficult to say precisely where the one begins 

 and the other ends. 



Of the 33 lower division veins enumerated by Dr Buck- 

 land, about seven are either thin, bad, or irregular ; so that 

 the division may be said to consist of about 2C workable 

 veins, of which 18 belong to the New Rock, and eight to the 

 Vobh^tcr scries. 



