226 Mr. M. Dunn on the Sinking of Preston Grange Engine Pit. 



No. VIII.— Narrative of the Sinking of Preston Grange Engine 

 Pit, from the Surface to the Great Seam, Seventy Fathoms, situate in 

 the Parish of Preston Pans, near Edinburgh. By Mr. Matthias 

 Dunn. 



Read, February 20, 1832. 



In order to illustrate by example the incalculable advantages of stop- 

 ping backwater in the sinking of deep mines, and also for the purpose 

 of exhibiting in a plain and practical point of view the arrangement of 

 the shaft, and the mode of applying engine power, I submit to the 

 Natural History Society of this town the following Narrative of the win- 

 ning of Preston Grange Colliery, executed under my direction, and in 

 the success of which I am greatly interested. 



The system of tubbing back the water found in sinkings, although 

 familiarly known to the professional gentlemen of this neighbourhood, 

 where it is so extensively practised, has nevertheless extended itself in 

 a very small degree to other districts, and has never, until the present 

 instance, been adopted in Scotland. 



In Ireland I also applied it, for the first time, in the sinking of one of 

 the Castle Comer Pits, in the county of Kilkenny, where a plank tubbing 

 of 10 fathoms long, supported by inside cribs, accomplished the win- 

 ning of a tract of Coal, without that method unattainable. 



By the invention of this principle, and the improvement of the steam 

 engine, the deepest and most valuable collieries in this neighbourhood 

 have been brought into work, and which had the effect of nullifying a 

 previously attempted monopoly of the coal district. 



In August, 1830, I laid before the Society of Arts, Edinburgh, a 

 description of this then unfinished work, as it was only completed to 

 the bottom of the second tub, with a view of establishing a claim to 



