168 Mr. Dunn on the Edge Seams of Mid-Lothian. 



AN ACCOUNT OF STRATA SUNK THROUGH IN GILMERTON ENGINE PIT. 



Flh. Ft. 7n. 



Hard Limestone Blaes or Shale, 8 



Soft Coal Blaes 4 



Vexam Coal, 14! 



Soft Blaes, 10 



Thin Coal, 6 



Freestone, 2 



Soft Blaes, 3 



Freestone, 9 



Soft Blaes, 3 



Hard Limestone Blaes, 2 



Thin Seam of Coal, 10 



Freestone, very hard, 5 



Soft Blaes mixed with Iron Stone, 6 



Thin Coal, 12 



Freestone, 2 



Soft Blaes mixed with Iron Stone, 5 



Coal, 12 



Ked Freestone, very porous, 26 



Hard Limestone Blaes, 23 



Total 96 1 2 



This stone forms the bottom of engine pit, and from which point is driven the level into 

 the Coal. See the annexed Profile, page 169. 



HORIZONTAL MEASUREMENT ALONG DRIFT. 

 From bottom of Engine pit in Limestone Blaes, to Limestone 



bottom 13 



Further in. Limestone, 12 



Ditto, Soft Blaes, 6 4 



Ditto, Parrott Coal, 1 0"| ^ j ^ 



Ditto, Rough Coal, 4J 



Ditto, Freestone, 2 



Ditto, Fire-clay, 6 



Ditto, Hard Freestone, 4 



Ditto, Soft Blaes, . 4 



Ditto, Hard Freestone, 5 3 



Ditto, very Soft Blaes, or Roof of Coal, 7 



Ditto, Parrott Coal, 1 ^l j ^ ^ 



Ditto, North Green Seam, 9 J 



Total Horizontal Drift, 43 5 2 



In 1829, the engine pit after two years and a half of labour was com- 

 pleted to the depth of 96 fathoms, but the Coal being found considerably 

 deeper than expected, and the power of the engine being well nigh 



