New Statistical Account for the Parish of Duddingston, Midlothian
(Written by the Revd. James MacFarlane)
Note: only the portion relating to coalmining has been included here.
Geology.—This parish abounds in coal, and previous to the year 1790, 270 work men were in constant employment. At that period, thirteen seams of coal were discovered, and partly wrought upon the grounds of Duddingston, and several of the seams were of a first-rate quality. The inclinations and dips of the minerals were to the west, and nearly at an angle of 45 degrees from the horizon to the east, which always rendered the working of the coal an extremely difficult and dangerous process, and which, in the end, was the cause of these mines being given up, as they could not be kept clear of water. When the lands of Duddingston belonged to the Duchess of Argyle, a machine, named "chains and basket," was employed to raise the water from a great depth. At the time this property was purchased by the late Earl of Abercorn in the year 1745, the coal mines were let to a Mr Biggar of Woolmet, a man of very considerable enterprise, who opened a level from the sea, in the form of a large drain, more than three miles in extent which he carried through the estates of Duddingston, Niddry, and part of Edmonstone, as far as Woolmet Bank. This extensive level proved of great advantage to the proprietors of the more elevated coalworks, but, in the end, completely ruined the collieries of Duddingston by an overflow of water. About the year 1763, the Earl of Abercorn, in order to clear the mines of this water, erected a powerful engine which extends its operations to the depth of fifty-two fathoms. This engine was rendered altogether useless in 1790, when, on 20th March, the whole seams were overflowed and choked from the communication of the level with the higher grounds. There may be mentioned also, that, before this time, another engine of even greater power had been erected near the southern boundary of the parish, to work the coal of Brunstanen. The shaft of this engine pit reached to the depth of sixty fathoms, and intersected three seams of coal; the first was seven feet thick, the second nine, and the last fifteen. The other substances through which it descended, were deep strata of a course red sandstone; and nearest to the coal, a kind of pyrite schist, which the workmen called "bands of blaes." There is much unexhausted coal in the parish; and the Marquis of Abercorn has lately leased the mines to an English gentleman. A powerful steam-engine has recently been erected, and it is expected that a large supply of coal will shortly be obtained.
On the beach at Joppa, immediately east of Portobello, successive layers of shale, sandstone, and coal, are distinctly visible. The stratum is here nearly vertical, and extends some hundreds of yards, yet it is only a small portion of the depth of the coalfield, and affords an instructive specimen of the partial elevations which take place through the whole country, and how difficult and matter it is to judge the actual position of the relative strata from such casual views. The quarry, at the same place, shows the northern portion of the coal seems exposed to view. [rest of this paragraph relates to other rocks etc]