0» Way-going Wuih in Coal-Mines. 



A creep frequently takes 

 place, occasioned by the hea\^' 

 pressure from above on the 

 great extent of the roof, and 

 the naturally insafBcient sup- 

 port of props and piUars ; which 

 creep always produces a. fall. 



A seam of coal of thirty 

 inches averages about sixty 

 bolls to the darg ,• and other 

 thicknesses in nearly the same 

 proportion. 



It is almost impossible to 

 work a seam of coal of less 

 than twenty-four inches thick, 

 but never a thinner one, ex- 

 cept where the roof is of stone 

 or some other hard stratum. 



Only some seams can be 

 worked. 



Unless the roof is of a con- 

 siderable degree of firmness, 

 the coal cannot be worked, as 

 is the case of the seam called 

 Belford Main Coal, the o^vners 

 of which were compelled to 

 abandon it on that account on- 

 ly, and thus at that time lost 

 the benefit of their coal. 



Great accumulations of ex- 

 plosive matter in the vacuums 

 between the pillars. 



The lives of alJ those down 

 in the coiiieri- are in constant 

 danger of sudden explosions, 

 and numerous j)er»on>. have 

 fallen victims to them. 



A sUght a-eep always takes 

 place, but is so slow and so 

 regular that it cannot bring on 

 a thll. 



A seam of coal of thirty 

 inches averages about eighty 

 bolls to the darg ; and other 

 thicknesses in nearly the same 

 proportion. 



A seam of coal of trvelve 

 inches thick is now working. 

 It is called Cupar Eye Seam, 

 and consists of two seams of 

 coal, which are divided by a 

 stratum of stone of three feet 

 thick : the top seam of coal is 

 fifteen inches thick, the bot- 

 tom one about twelve inches. 



Every seam can be work- 

 ed. 



Tlie roof being of a soft or 

 tender stratum is not a pre- 

 ventive to working the coal, 

 as in the instances of the seams 

 called Belford Main Coal, and 

 BulmanMain Coal: at the lat- 

 ter place they work from dip to 

 rise, being a length of roof of 

 one hundi-ed and forty yards. 



No explosive matter can 

 accumulate, neither coal nor 

 vacuum being left. 



No life has ever been lost 

 by explosion ! ! — It would be 

 impossible for such a circum- 

 stance to occur; because the 

 gases alluded to being of a less 

 sjx-cific gravity than the at- 

 mospheric air,ihey fly instant- 

 ly (as the coal comes down) 

 to the foot of tlie shaft, ascend 

 to the surfiice of the earth, 

 and l)ecome neutralized. 



