1838] 



FARMERS' REGISTER, 



707 



earth ; but there is no doubt, that, in many eases, 

 it might prove equally surcetisliil, and be of es- 

 sential importance in those of n)ines and quarries, 

 where the \vorkin<rs are often obstrucied bv a tiow 

 of water, which miofhr be diminished belore it 

 reach the mine, ani be parly ixot (jiiit of, when it 

 does reach it, in a manner more easy, and as el- 

 fectnal as by the ordinary methods.* 



It has been explained, that all sprinffs and sub- 

 terraneous collections of water, are sup;)iied li"om 

 •rroitnt! lying hiirher than that where they are 

 /()uud, thouirh which the rain and other water de- 

 scends, followinfj the coarse of snch rock, snnd, 

 or gravel, as far, oras deep, as they extend. Thas, 

 in sinkinor a pit tiircoal, or other mineral, near the 

 bottom of a hill or eminence, a bed of quicksand 

 is often met with, so (ill of wMter, <hat to pass 

 throucih it becomes a tedious and ililficiilt opera- 

 tion. As this water musi come from the hiirher 

 jgroim I, above where the pit is sunk, it mav be 

 ipessible to intercept the irreafer pari of it before it 

 •reach t\io sand bed ; and if the trround declines 

 lower rhan the level at which the sand bed ap- 

 pear s in .the pit, by a drain and boring, the whole 

 wafer mav be drawn from it at that lower poirU. 

 To accomplish this object, it will he necessary to 

 ascertain what strata lie above the place where 

 the pit is sunk ; and, for that purpose, it will be 

 proper to examine if the termina'ion of any ben 

 of rock, snnd, sravel, or other oorous snhrJtances. 

 appears hitrher on the acdiviiy. which mav con- 

 vey the wafer it contains to the inferior strata 

 through which the pit is to be sunk, ff one or 

 more of these b'^ds are found, and water issue 

 from hem, as may be seen by the stirface, a drain 

 :shou!d be cut in the manner already directed, 

 which win carry off a great part of the water, and 

 consequently lessen the quantity in the pit or 

 mine. Bui, when this is done; and the suppl_\ 



* By expensive engines for the purpose of drawing 

 it U|). 



from above thereby diminished, or nearly cut off, 

 still a quantity of water that may be troublesome 

 will flow from the sides of the sand bed, which, 

 however, may be drawn off at some point in the 

 low ground. To ascertain this, it will he neces- 

 sary to examine, from the pit, along the d(;ciivity 

 towards the lowei«!t ground, in order to disco- 

 ver whether the s;uid bed continues lower, and at 

 what point it lermmates. This may be f()und by 

 a|)plyiuir a snirit-level ; and if it appears tliat at 

 that point the water has a natural outlet, it may, 

 by means of a deef) drain, |or boring, he mnre quick- 

 ly and etfectuallv drawn off; for, asa natural spring, 

 it may have only a narrow and slow passa<j;e, but 

 where a larixer and lower opening is made, the 

 water will discharije itself in greater abundance. 



This operation may tend, in a great measure, to 

 remove, or at all events will relieve the difficulty 

 that mi<>ht afterwards attend the sinking of" the 

 pit, and also the workings below ; fiir the water 

 thus cut off might have foun<i its way down- 

 wards, passiriiT fi-om stratum to straium, so far an 

 such coruinued porous, or capable oi receiving if. 



It is therefore of material advantage to drain all 

 ground lying hio-lier, or cnntiguous to subterra- 

 neous pits ami mines; and, on these principles, 

 and iiv these menus, it may be done with little 

 difficulty or expense. Water found in the bottom 

 of the pit, or in the course of the mine, nmst he got 

 nd of in a difTerent manner, as the grotind may 

 nowhere decline so low as to be under that level ; 

 li:>r it is only on the supposition of' the different 

 strata and sai'd bed havinsr the same inclination 

 with (he surface, or Ivinij nearly horizontal, that 

 the above is practicable; but, if they lie in a reverse 

 position, there is little hope of ac'complisiiing the 

 <)l)ject, imless their termination can be hit on 

 somewhere in the opposite side of the hili, which, 

 by exact ievellinfr, and asceriaitiingihe precise in- 

 clination of the metais, may be found out. See 

 Plate Nr. XV. 



The water which collects in the mine itself, in 

 the course of working, can only be got rid of by 



Plate X-V.— Section represeniing the draivins of mines. 



'.Conf-ainina :''^i 



y.Poi' OiLsJjody Jiavina <tcommunical'ion'_^ 

 ===^ w//h Hie bii/cA Sand in .^y-"^^ 



Subjacent mineral strata, into wiich the pit is to be sun'c. 



A, Drain cut into the tail of the sand, or rock— N.B. This will cut otr the water w^ich flows out of the 

 rock, or sand, asil which, after rur.nins o\erthe surface of the c'ay. '- ih-orbcdbv thp next porous soil, through 

 which It descen.fs into the quick-sand that imp'-dcs the sinking ni the pif. or ( xcavatioii ot the n.ine. 



B, Draui cut through the sand bed. S S, Springs. 



