GARFOHTH : DEEP MINING. 
475 
Within the last few years several mines have been opened out 
between two and three thousand feet deep, and it ma)^ therefore 
assist in the consideration of this matter to state what has been 
actually proved. 
At Ashton Moss on a level with the shaft bottom (viz. 2850 
feet) or down the incline at a depth from the surface of 3036 feet the 
temperature varies from 85 to 87 degrees. The air is dry at the 
coal face, and the moisture which was expected would be given 
off and prove an obstacle, has not proved to be the case. The 
workmen up to the present have worked about the same length 
of time as those employed in the shallower pits, say 7 to 8 hours, 
without suffering any serious inconveuience. No complaints have 
been made that the high temperature has affected their health. 
There is no difficulty in obtaining labour. The men drink 
large quantities of cold tea, coffee, or water, and appear quite as 
healthy as men working in other pits, though it must be admitted 
they cannot work with the same energy and vigour which is a 
characteristic in the shallower pits. Fortunately the same physical 
force is not required, as the superincumbent weight acting upon 
the coal renders it easier to get. 
The men do not appear to be affected by increased barometric 
pressure equal to 3? inches of mercury over and above that on the 
surface. This pressure is a trifle compared with that withstood by 
sinkers in working the pneumatic process. 
The quality of the coal now being worked at great depths is 
admitted to be quite equal to the most valuable seams hitherto 
worked, indeed deep seams are, generally speaking, superior to mines 
lying nearer the surface. No water has been met with except a few 
drops with a saline taste. The quantity of gas given off from the 
mine is no greater than in shallow mines. Some mines which might 
be mentioned lying at one third the depth give off a greater 
quantity of gas than the deep mines referred to. 
No difficulty has up to the present been experienced in ventila- 
ting the mine. The strata being inclined the ventilation is conducted 
on the ascentional principle by means of a furnace. Owing to the 
long motive column a large volume of air is circulated through the 
