The cost of working having thus been given, I wish now to lay before you an explanation of the method of working and bringing the coal to the surface. It may not be uninteresting to mention how many men are employed in this work, as the number is very large. Coal was not formerly excavated by machinery, but it is so now, and therefore hands must be had. The number of men employed in the mines of county Durham in 1854 was 28,000; of these, 13,500 were hewers, winning several thousand tons of coal daily. Of the remainder, 3500 were safety-staff men, having, besides, 1400 boys belonging to their staff; 2000 were off-hand men, for bargain work or other duties; 7600 lads and boys, working under the various designations of "putters," or pushers of coal-tubs, underground "drivers," "marrows," "half-marrows," and "foals," these latter terms being local, and significant of age and labour. For Northumberland must be added 10,536 persons, and Cumberland 3579, making a total for these three counties of upwards of 42,000 persons labouring in and round our northern collieries. The average that each hewer will raise per day is from two to three tons in thin, and three to four tons in thick seams. The largest quantity raised by any hewer on an average of the colliers of England is about six tons a day of eight hours. The mode of working is very laborious, as the majority of seams of coal being very thin--that is to say, not more than two feet thick--the worker of necessity is obliged to work in a constrained position, often lying on his side; and you can fancy the labour of using a pick in such a position. To get an idea of the position, just place yourself under a table, and then try to use a pick, and it will give you a pretty clear idea of the comfortable way in which a great part of our coal is got, and this also at a temperature of 86° in bad air. The object, of course, of the worker is to take nothing but coal, as all labour is lost that is spent in taking any other material away. The man after a time gets twisted in his form, from being constantly in this constrained position, and, in fact, to sit upright like other men is at last painful. Then an amount of danger is always before him, even in the best regulated and ventilated pits. This danger proceeds from fire-damp, as one unlucky stroke of the pick may bring forth a stream of carbureted hydrogen gas, inexplosive of itself, but if mixed with eight times its bulk of air, more dangerous than gunpowder, and which, if by chance it comes in contact with the flame of a candle, is sure to explode, and certain death is the result--not always from the explosion itself, but from the after-damp or carbonic acid gas which follows it.