330 THE CARBONIFEROUS SYSTEM. 



former, raid being the next in the series in descending order. They 

 dip to the north-east at an angle of 20°, or about 1 in 2J. The thick- 

 ness of the main seam is so well known that it is unnecessary to give 

 a section of it. Its average thickness may be stated to be 38 feet. 

 Several shafts have been sunk to the seam, the workings in connexion 

 with which have received a peculiar classification, which had its 

 origin in the following circumstances : — A large tract of workings to 

 the rise of the shafts, which are distant from the crop 250 yards, 

 extending 800 yards to the west and 200 yards to the east of them, 

 and covering an area of about 40 acres, forms the earliest worked 

 portion of the seam. In nearly the whole of this district about 12 feet 

 only of the upper part of the seam has been woi'ked, the lower portion 

 being considered inferior in quality. These . workings are locally 



Q known as the "burnt mines," and are so designated in consequence of 

 a fire that occurred some years ago in the stables, and was only extin- 

 guished by closing the shafts to prevent the admission of the air into 

 the mines. Further to the dip other shafts have been sunk, and they, 

 with some situated 960 yards to the west, and known as the Dalhousie 

 pits, are the present working shafts. From the former of these the 

 workings were considerably extended both east and west ; they are 

 in the upper part of the seam only, and their extent is about 90 acres. 

 In some workings to the dip of these an accident occurred in May 

 1861, which was attended with still more disastrous results than the 

 preceding one, it being found necessary to fill the mine with water in 

 order to extinguish the fire. An attempt was made to get into these 

 workings in 1862, but their condition was such that they were aban- 

 ° doned, and this district, from this circumstance, has received the name 

 of ' Crushed Mines,' — a designation sufficiently indicative of the state 

 of the workings on re-opening the mine. 



" The main seam is at present worked on the east side of the 'Crushed 

 Mines,' and in the Dalhousie pits on the west side. In the latter, 

 the seam has been worked the entire thickness, the lower portion being 



<0 much improved in quality. The extent of workings in this district 

 is now upwards of 100 acres. 



" The difficulty of working a seam of such a thickness and with such 

 a declination has unfortunately been exemplified during the last two 

 years in this district of the mine. Whilst the modus operandi re- 

 mained the same, a change appears to have been made in the scale of 

 Q5 pillarage to meet the requirements of so largely an increased height of 

 seam, which, however, proved inadequate, and a large extent of workings 

 has been and still is under the effect of a crush in consequence. 



" The system of working pursued from the commencement of the 



