120 Mr Bald mi the Coal-field 



This exhibits a body of workable coal altogether uncommon, 

 and is of the highest importance and value to the capital of 

 Scotland for affording a supply of coal for many generations. It 

 is, however, particularly to be remarked, that this astonishing 

 thickness of coal is found not to extend the whole length of 

 the basin, from the sea at Fisherrow to its western extremity at 

 Magbie Hill and Carlops : the coals continue only to the great 

 road leading from Edinburgh to Dalkeith at Sheriff-hall, where 

 there is a dislocation, which throws the coal strata up to the west; 

 and has the effect of throwing off all the valuable flat coals, as 

 they are not to be found westward of that line ; and it appears 

 that the flat coals found at Eldin, Polton, Dalhousie, and 

 Whitehill collieries, are part of the edge-coals rendered flat by 

 the slip or dislocation. 



This coal-field extends to the south side of the Roman-camp 

 Hill near Dalkeith, and takes a reverse dip to the south ; then 

 deflects, and rises again to the south near the village of Ford. 



I have now to make the following remarks on this coal-field 

 and sections. 



All the coals are of the common bituminous kind, partly 

 splint and partly cubical coal. 



The strata betwixt the coals are Various shades of yellow, white, 

 grey, and bluish coloured sandstone, argillaceous schistus, bitu- 

 minous shale, argillaceous earth, named Fire-clay, and a little 

 coarse clay limestone in some places. All the coals are of open 

 burning quality : — no caking coals have ever been found. 



The coals lie, in general, at the common distances from each 

 other, as in other coal-fields, with this remarkable exception, that 

 betwixt the coal marked No. 34. in the section, and the next 

 coal under it, marked No. 75., the distance is no less than 90 

 fathoms, or 540 feet, in which space there is no coal. I know 

 of no such thickness of strata in a coal-field without a coal being 

 found ; and it is a fact of great importance in the searching of a 

 district for coal. 



There are no beds of greenstone found in the strata hitherto 

 explored, although there are several vertical dikes or veins of 

 this rock, which intersect the strata seen in the Port-Seaton dis- 

 trict along the shore. 



