Ml VINO. 



other u on winding, and both p*M over a pulley placed above the .haft, 

 having Urge ironbuckeU or kibble* attached to them, which by thu 

 arnuiRrmrnt are kept alternately ascending and defending, one ki ' !!. 

 being loaded at the bottom while the other is emptied at the surface. 

 Tnii apparatus u termed a " whim " in Cornwall, but in the north of 

 England a " whinuey " or " gin." Where mines are not very deep it U 

 a convenient auxiliary in the extraction, but is only useful for drainage 

 when the quantity of water is very trifling, u in sinking a mere trial 

 shaft. (See Fig. 5.) 



Fig. 5. 



Water-icJieel. When the influx of water in a mine become* at all 

 considerable, recourse must be had to the power either of water or of 

 steam to discharge it to the adit, or the surface, as the case may be. 

 Should local circumstances be favourable to the application of water- 

 power, it will of course have the preference, being recommended both 

 by its economy and steadiness of action. The nearest stream of water 

 available for this purpose will be turned into an artificial watercourse, 

 or " leat," and conducted to the mine so as to obtain a sufficient fall to 

 turn an overshot water-wheel, whose diameter and width will be regu- 

 lated to receive it. Where a constant and abundant supply of water 

 can be obtained, this power becomes extremely valuable, and the miner 

 avails himself of it with great ingenuity, constructing large reservoirs 

 in the valleys through which the stream passes, to render the supply 

 more equable in time of drought, and erecting as many water-wheels 

 on the mine, each receiving its supply from the tail of the other, as the 

 declivity of the ground will admit. The water- wheels vised in mines are 

 invariably overshot ; they vary from 10 or 12 feet in diameter to more 

 than 50 feet, and from 2 or 8 to 6 or 7 feet in breast: some of the largest 

 exceed 100 horse-power. The German miners have long been celebrated 

 for their skilful application of water-power which, from the mountainous 

 nature of their mining districts, early presented itaelf to their notice. 

 In this country, from the general application of the steam-engine to 

 the drainage of mines, water-power has been less cultivated ; but many 

 fine instance* of it* use may be seen in some of our mines, where cir- 

 cumstance* have been favourable to it* adoption. Among these may 

 be named the Fowey Consols Mines in Cornwall, the mines of Whcal 

 Friendship and Wheal Betsy in Devonshire, and of Orassington in 

 Yorkshire. Tlie application of a water-wheel to the drainage of a mine 

 is shown in / 



Pump. Luring the erection of the water-wheel pump* are fixed in 



in size to the quantity of water to be drawn 



nch in diameter being a very common size, where there u 



rate influx. The pumps iu*<l in mine* do not act at all 



by atmospheric pressure, as in the case of the common household 



pumps; they are arranged in "lift*," ,. of considerable 



height, often indeed from 20 to 80 fathoms, the water being discharged 



into cisterns placed at the foot of each, and railed entirely by lifting 



or by pmsure. Th construction and arrangement of the pump-work 



form* a very important branch of ruining, and one which, from the 

 great depth of our mines, and the vast influx of water so coron 

 them, has been much cultivated in this country, and consequently 

 brought to great perfection. Wooden pumps were formerly common 

 in mines ; but they have for a long while been entirely superseded by 

 iron ones, which admit of the lifts being carried to a great height 

 without leaking, or the danger of bursting. The whole column of 

 pump* in a shaft is commonly worked by a single pump -rud, which 

 goes down the middle of it and communicates with each column by a 

 rod attached to it* aide. In order to give a reciprocating mo; 

 the main pump rod, a crank on the axle of the water-wheel is attached 

 to one end of a horizontal rod, the other end of which is fixed to an 

 apparatus termeda " bob," consisting of an upright post moveable on a 

 centre, and firmly braced to a horizontal piece framed into it at the 

 I .'tti.iu, tin- further end of which is connected with the pump-rod. In 

 this manner it will be teen that the rotatory motion of the water- 

 wheel is converted into a steady reciprocating motion when comiuu- 

 * nicated to the pump-rod, the weight of which in always counterbalanced 

 by a large box filled with stones, old iron, &c., which is attached to the 

 opposite end of the balance-bob. (See Fig. 6.) 



As the power of the water-wheels used in mines is entirely due to 

 the gravity of the water, or the force it exerts in falling thi > 

 given space, minus the effects of friction, it is only where a consider- 

 able stream can be obtained that water-wheels of sufficient power can 

 be erected; but in cases where the supply of water i< very limited, 

 nnd it is practicable to obtain a considerable fall,' there is loothi 

 ingenious mode of applying it, by which the principle of hyu 

 pressure is called into action. This contrivance is termed the " 

 pressure engine," and is a good deal used in the German mines, though 

 only to a limited extent in this country. The principle consists in 

 giving motion to a piston by the alternate pressure of a high column of 



u liirh having performed its office, the communication is cut off, 

 iv. net- in the cylinder escapes. The apparatus is not in fact 

 unlike the working portion of a steam-engine, the hydrostatic pressure 

 of a column of water being substituted for the force of elastic vapour 

 and the reciprocating motion thus produced may be directly applied to 

 set the pumps of a mine in action. 



Steam-engiac. From the great abundance of coal which exists in 

 this country, and the cheap rate at which it can be generally 

 obtained, the steam-engine has long been the great auxiliary of the 

 Knglixh miner, and in its present improved state it has greatly contri- 

 buted, as before noticed, both to the perfection of our mining system 

 and the enormous extraction of minerals and metallic substances by 

 which our mines are distinguished. In our coal-mines, where the fuel 

 U of scarcely more than nominal value, the steam-engine is the only 

 power ever employed for drainage, and in all deep and extensive works 

 for extraction also. In our copper, tin, and lead mines, on the con- 

 trary, where the carriage of coal renders the use of it more expensive, 

 water-power is always, as far as possible, rendered available. In all the 

 deepest and most extensive mines of this description the steam-engine 

 i> however indispensable, and both the drainage and extraction have 

 been in great measure performed by it, since its use has been so 

 greatly economised by the reduced consumption of coal con,- 

 upon late improvements. 



ni.itory and progressive improvements of the steam-engine are 

 BO intimately connected with its general application t.. mining pur- 

 poses, and consequently with the present perfection which the art of 

 mining has attained, and the vast produce afforded by our : 

 that it requires some brief notice here. The eilieiem-y of a 

 engine for mining purposes is estimated in Cornwall (win 

 great expense of coal, all the late improvements have originated) by 

 the standard termed duty, which accurately and conveniently define* 

 the work performed, with reference to the consumption of a given 

 quantity of coaL Thus, by the duty of an engine is expressed the 

 number of pounds (always millions) of water which have been raised 

 through the height of one foot by the consump' nhel of coal, 



the data for this calculation being the quantity of water discharged 

 from the pmn| in a given time, and the quantity oi , !10 d by 



! in the same period. This mode of calculating t ' 

 of steam-engines was practised by Watt, who thus estimated the Having 

 of fuel effected by his engine compared with the atmospheric engine pre- 

 viously in u, i ,,f this naving being the rcn, !,nn d 

 l.y him for the use of his invention. An admirable system for the 

 registration of Uie duty and other peculiarities of the engines employed 



vail was organised in the year 181- m has been 



f continued, the results being monthly ascertained and pub- 

 lished in a convenient form. The effect of this system has been to 

 excite an extraordinary degree of competition am. : ineers, 



each of whom strives to improve the duty oi .n>s in every 



possible manner. The improvements which thus resulted were so 



ted and so oxli . to excite suspicion and 



d ul ity among those engineers who rend, d in other part.* of Kngland, 

 which have only been removed by the most rigorous scrutiny and 



progressive impi ; the duty of .< lia* 



ry accurate . Mr. John Taylor, in his 'Records 



of Mining;' and the following is a summary of the result* which In- 

 obtained :- 



