14 Mr. N. J. Winch on the Geology of 



sections of Hebburn and of Sheriff hill, as exhibiting when taken in 

 succession, a series of Coal measures of the thickness of about 270 

 fathoms. In the former colliery are the beds which lie above the 

 High Main coal ; in the latter principally those which lie beneath 

 it ; together they present the entire order of the coal seams, that are 

 best understood in the Newcastle district : but it will be seen even 

 in these two examples, what want of agreement there is in the beds 

 which lie in the two sections above the High Main coal. 



The most valuable seam in the whole Coalfield in point of thick- 

 ness and quality is that called the High Main, of the mines situated 

 between Newcastle and Shields. It there averages above 6 feet from 

 the roof to the floor, contains a large proportion of bitumen, and 

 is sufficiently hard to bear carriage without breaking into very small 

 fragments. From this the owners of Old Byker, Byker St. Anthony's, 

 Walker, Walker Hill, Willington, Old Benton, and Flatworth mines, 

 formerly drew their riches ; and it continues to supply the present 

 proprietors of Hartley, Blyth, and Cowpen, north of the 90 fathom 

 Dyke; of Heaton, Bigge's Main, Wall's End, Pevey Main, Colling- 

 wood Main, and Murton Collieries on the north side of the Tyne, 

 and of Hebburn, Jarrow, and Manor's Wall's End, on the south 

 side of that river. I have already described in part the basseting 

 of this coal seam along the course of an oval line, of which Jarrow 

 is the centre ; from which some idea may be formed of the extent 

 of country which it underlies north of the 90 fathom Dyke. At 

 a land-sale pit, a little above the Ouse burn Bridge, near Newcastle, 

 this seam was found at 14 fathoms j but on the Town-moor, from 

 the numerous vestiges of ancient pits, it appears to be exhausted. 



The lower seams under the same lands are without doubt un- 

 touched. Wallis, in the history of Northumberland, gives an 

 account of a fire happening in the High Main coal, about 140 years 



