MINING, COAL. 



HTHOB. 



I contrivance are naoasssry at every stop of the miner'* 

 nmcress, * circumsUnoe which renders a knowledge of mechanic* 

 mdEi|Moeable ; and in punuing the complicated operation! of under- 

 ground diwuvery, luos and error can only be avuidwi by the aid of 

 geometry and subterranean surveying. 



Thus then we may perceive that, in addition U> practical knowledge 

 in mining, there is a wide scope for the aj>plicatiou of scientific know- 

 ledge aim ; in fact, it ia continually in requisition, not merely in the 

 general arrangement*, but in the detail* also, and ought therefore to 

 be possessed, to a certain extent, by the mining pinna*. Among those 

 nation* of Europe by which mining U most successfully cultivated, 

 the value and necessity of scientific knowledge among miuers have 

 long been perceived, and ample provision* have been made for iu 

 attainment, a* may be seen in the mining-schools of France nnd 

 Germany. Although Great Britain possesses the richest and m.-i 

 productive mines in the world, it in remarkable that, till within the 

 last thirty years, nothing was done iu this country to provide the 

 means of instruction for those who arc designed for tlio profession 

 of mining Thuii both the working miner and the mine agent had, 

 iu this country, no knowledge whatever of the principles mi which the 

 success of tlu-ir !] r.itiiiti.4 depends, but proceeded entirely upon the 

 practical skill acquired in the coune of their experience. 



ilimimg School*. When treating of the history of mining at the 

 beginning of this article, the establishment of several institutions for 

 the attainment of those acquirement* which are needed in the professions 

 !!' civil engineering and milling was noticed as forming the most 

 recent event connected with the subject, and in course of time 

 the benefits thus derived will no doubt be strikingly apparent. 'I'll.- 

 mining-school of Cornwall formerly placed in operation by Sir Charles 

 Lemon, might have supplied able miners well instructed in all that 

 relates to the working of our tin, copper, and lead mines ; while the 

 university of Durham will, it is to be hoped, produce mining engineers 

 whose qualification!) will have a more especial reference to the working 

 of coal and other minerals which occur in the stratified rocks of the 

 north of England; and the School of Mines at Jermyn Street, v. ill 

 tend to systematise and diffuse the knowledge of the more general 

 principles of mining. Thus by introducing a system of sound mining 

 education, and by the continual progress of science, aided by the 

 effort* which are now being made by government to supply desiderata 

 which have long been required by the mining interest, we may hope 

 still to maintain our mines in a flourishing condition-, notwithstanding 

 their depth, their heavy expenditure, and the increasing competition 

 of other countries. 



The total quantities of the metals raised from English mines, in 

 1858, was given by Mr. Hunt, as follows : 



Tin . 



Copper 



Zinc . 

 Iron 



0,920 tons. 

 14,456 

 68.SOS 

 509,545 ounces. 



6,900 tons, 

 3,436,064 



value 823,480 

 1,562,693 

 1,489,005 

 156,369 



., 174,225 



10,713,798 



Total 14,919,770 



MINIMI, COAL. Although it would be impracticable to enter 

 upon the various modifications of mining processes which are required 

 in the working of all the varied natural depositaries of mineral wealth, 

 the peculiarities of coal-mining are such as to require a brief notice, 

 important and extensive as are the coal-mines of this country, and the 

 arts and manufactures supported by thorn. 



The nature and distribution of our carboniferous deposits have been 

 already fully described in the articl u,s, in NAT. HIST. Div. 



In working mine* of coal, or indeed of iron-stone or rock-salt, and 

 other minerals which are found in beds, the object to bo attained is 

 the effectual opening and extraction of a tolerably uniform -""T of 

 small thickness, but of great horizontal extension. The process thus 

 differs considerably from the working of mineral veins, where the 

 object of research in fluctuating and irregular in its produce, and 

 either vertical or highly inclined iu it* position. The thickness of 

 beOs of coal may be said generally to vary from three or four to 

 eight or nine feet, although sometimes, when several seams come 

 together without any intervening layers of rock, they may expand 

 y or thirty f.et, of which we have an example in the "ten- 

 J " of Staff irdnhiro. In every coal-field there ore many """ 

 at coal at gnat, r .-r lew intervals, one U-W another, of which on 

 many as three or four arc frequently worked in the name mine : and 

 intantratified with the ruck which divides them there are in many 

 coal-field, extremely productive beds of ironstone, which are wrought 

 at the same time, and in a similar manner with the coal 



The mode of working coal-mines will bo most clearly understood by 



Hang the works from then- commencement, in the same manner as in 



SZZnjS^i , Kr T , UW IS"* ** ^cation ,,f coal and the 



Jonof its bed. over very considerable, area,, it i. pretty 



2i!L*V* ?* tt p m ""to for il - if " 



dgrnent fhe ,-robaMe existence of bod* of . 



"ruined, and perhaps the bods themselves di^ 

 Mverad by boring, the first process is to sink s perpendicular shaft 

 from Uw surface so a. to intersect the various straU wntaining the 



coal, and of course as many of the beds of coal as are considered to be 

 worth working. The shaft is generally circular, and may vary accord- 

 ing to circumstances from six or seven to eight or ten feet in .i'i 

 the upper (hirtion, as far down as the solid rock, is eitlier 1 nicked or 

 walled, and where the ground is weak this casing may be eon 



ut. On reaching the first workable seam of coal, the sinking 

 of the pit in for a time suspended, and a broad straight passage termed 

 a " bord " or " gate " is driven from it upon the seam of coal, in opposite 

 direction*. The breadth of the passage is usually twelve or fourteen 

 feet, and it is formed the whole height of the seam of coal, so as to 

 expose the stratum above, which is called the " roof," and the one 

 hi.-h ] - teriiu .1 the " thill," and its direction is always arranged 

 BO as to follow the cleavage of the coal which forms its sides, . 

 thus present a clean uniform MII face. When the bord or "in 

 gate has proceeded some distance on both aides of tho pit, narrow 

 passages, termed * headways," are driven from it at regul. i int. 

 and exactly at right angles ; and when these have urocc- 

 ten yards, they are made to communicate with another bord, \v! 



i parallel to the first and on each side of it. It will be seen that 

 by continuing this system of excavation the bed of <>.] will be en- 

 tirely laid open and intersected by a series of brood parallel passages or 

 bords of about eight yards ajiart, communicating with each otl 

 narrower passages or " headways," which cross them at right angles, 

 and likewise traverse the whole extent of the mines ; immense square 

 or rectangular pillars of coal being left standing between the two. A 

 coal-mine in this state is not in fact unlike a regularly-built town ; the 

 bords and headways may be compared to the principal streets and tho 

 narrower streets which cross them ; while the pillars of coal may be 

 said to resemble the intermediate masses of buildings. 



The water encountered in the above operations is drawn to the 

 surface by a powerful steam-engine erected on the shaft, which is so 

 arranged as also to raise the coal and rubbish, for which y 

 " corves " or baskets are commonly employed. Supposing the 

 operations to have been successful as regards the prospects of tin- mine 

 another shaft will now be commenced at some distance from the first, 

 and when the communication between them has been effected, the one 

 being made the downcast and the other the upcast, the air is conducted 

 from the latter to the former through all the bords and workings, 

 which it must traverse in succession in consequence of " stoppings " or 

 doors which are fixed in various places to obstruct its progress and give 

 a proper direction to the current passing to tho upcast shaft. Till 

 such communication can be formed, the first shaft may be divided by 

 a " brattice " or partition, and be made to answer the purposes of 

 both ; some few coal-mines are indeed worked entirely in this in 

 but the danger of explosion is considerable when the workings become 

 extensive. 



While the workings on the first seam of coal are thus going on, the 

 shaft may be sunk to a second or third seam, where similar operations 

 will be commenced, small underground pits or " staples " being wink 

 at intervals from the workings of the upper seam to those on the seam 

 below, by which ventilation will be promoted. These operations, like 

 those described in the former article, may be carried on 

 and will thus in time form an extensive colliery. The regular i- 

 uniformity of the working however are greatly modified by the occur- 

 rence of faults and other local accidents, and the pillars themselves are 

 finally removed to such an extent as to cause subsidences of the roof 

 and undulations of the floor, which present a most frightful appearance 

 i ! i -.-!-. 



The mode in which tho pitman carries his excavation upon the coal 

 is by cutting a narrow fissure in the seam on each side of the bord, 

 and undermining the coal between, finally detaching the great cul >ical 

 mass thus circumscribed by putting in two or three shots, which are 

 simultaneously fired at the top of the seam. From 60 to 80 or 10< 

 tons of coal may thus be brought down iat on.-.-, when it is put into 

 corves drawn along a tram-road to the shaft, and thence raise. 1 l.y a 

 steam-engine to the surface, where it is often passed over gratings or 

 "screens" in order to separate the small pulverised coal from the 

 larger masses, which in coal countries ore alone valuable. 



In mines which ore not endangered by explosive gases or " lire 

 damp," the coal-miner or " pitman " is guided iu his operations l.y tho 

 usual subterranean light a small caudle stuck into a piece of 

 clay ; but where the fire-damp is apprehended the safety I 

 which has long superseded the primitive contriv.-nice of the steel mill, 

 tho light of wlu'ch was produced by the contact of a flint with the edge 

 of a wheel kept in rapid motion. Notwithstanding tin; uw of the 

 Davy lump, and the improvements which ha\ 

 tii 'ii, accident* from explosion are unfortunately .-(ill of f>. 

 occurrence, although perhaps in most oases they may bo traceable to 

 some neglect or imprudence on the p.-irt of the men themselves. 

 Att'-mpt* have recently I I w 1 t<> the lighting of 



tin-mines and coal-mines, both iii Knglniuland in Belgium; l.nt hitherto 

 without success. 



Tho quantity of coal raised in Great liriuin in 1858, was not less 

 than i;:..iiii\i!|!P tons. 



-MIMl'M. [LEAD: lied Lead.] 



M1XOU (Latin), Ltu, or Later, is a term used to distiniruixh tho 



y that takes a minor 3rd. It is also . II the 



diatonic intervals, but chiefly to tho 3rd. The minor 3rd comprises a 



