The Thick Coal of South Staffordshire. 415 



inferred from the character of the several members of the series ; 

 but the main difficulty presents itself in the small amount of 

 foreign material which, over an area of many square miles, 

 separates the distinct beds of coal, which collectively compose 

 the ten-yard seam. 



As before mentioned, the general method of working this 

 valuable deposit is considered one of the most wasteful 

 which could be adopted. Though there are two acknow- 

 ledged plans of getting the thick coal, only one is prac- 

 tically followed, the other being confined to the estates 

 of a few of the most intelligent proprietors. The common 

 course is to get as much of the entire seam as can be 

 extracted with anything like safety to the roof, which is left 

 supported by gigantic pillars, the spaces from which the coal 

 is cleared being called " stalls," The first stage in the process 

 is to make the necessary galleries into the coal. These are 

 termed " gate roads." Out of these the stalls are opened. 

 The " holers " undermine a face of coal, after which it is 

 brought down in as large masses as possible, and it is these 

 falls which are so productive of accident to the miners. The 

 ventilation is carried on by means of air- ways running parallel 

 to the gate roads, and communicating with the "sides of 

 work '" and though this plan is very imperfect, the seam is not 

 generally charged with much fire-damp (or " sulphur," as it is 

 locally defined), so that accidents from explosions are not fre- 

 quent in thick coal workings. After the whole area has been 

 gone over in the manner above described, the pillars are taken 

 down in a second operation ; and if the ordinary method of 

 mining is dangerous, this is much more hazardous. After this 

 process of getting the "ribs and pillars" is completed, the 

 overlying materials, and of course the surface of the ground, 

 rapidly sink, causing buildings to crack and fall to pieces, while 

 not unfrequently, when a pillar is removed, the superincumbent 

 mass falls, making a yawning chasm like a crater. These 

 " crownings in" are very common when the coal does not lie at 

 any great depth. The other and safer method of getting the coal 

 is by what is termed the " long wall " system. The upper mea- 

 sures are first worked out completely, and the ground is allowed 

 to "settle." Afterwards the remainder of the coal is extracted 

 in a similar manner. The gate roads are first driven to the 

 boundary, after which the beds are worked in long " sides," 

 back towards the shafts, and the roof is allowed to fall in as 

 the mining processes proceed. 



It has been stated, on the authority of a gentleman well 

 acquainted with the working of the thick coal, that the actual 

 amount of material in this seam may be put down at 48,000 

 tons per square acre ; but of this only about 24,000 tons can 



