xiv The Author's Preface. 

 Penfibly necefiary for carrying on a mine-work. 

 The former, in order duly to reach home to the 

 proper depth, and through fuch fubterraneous ca- 

 nals to drain off the water into a valley •, in or- 

 der thus to fuperfede the ufe of expenfive en- 

 gines. The latter, in order not only to timber 

 and fecure, where needful, the jhafts and drifts *, 

 but alfo fmelt and work the ores for their metal. 

 Now, as to levels, our forefathers have, for in- 

 flance at Friberg, left us fuch extraordinary works 

 in this kind, as that, in want of them, our mines 

 would become quite impracticable ; particularly 

 that called the prince's level, one of the grandeft 

 works in thefe parts, confidering the time, la- 

 bour and expence neceflary to work a pafiage 

 under ground through firm rock, for about five 

 Englifh miles in length. As to wood, the want 

 of that in particular difqualifies many places for 

 mining. The expences at the day in aqueducts, 

 trenches, ftamping and wafh works, in engines, 

 in conftructing the fmelting and other huts, in 

 wooden trunks, good additions + or fluxes, fervice- 

 zbtejlags or fcorias, &c. Things abfolutely ne- 

 ceffary in the bufinefs of fmelting, come very 

 high in fome places, but not fo in Mifhia. Nor 

 muft I omit mentioning to our honour, that both 



for 



* Drifts are hqr.2C>ntal paflages, .much in the nature of levels 

 defigned either for going upon a vein, and digging out the ore ; 

 for conveying off the water, or for conveying the ore to its 

 place of collection, or the bottom of the fhaft. 



+ By additions fmelter's mean thofe matters added to their 

 ores, in order to procure their yield, or to work them to bet- 

 ter igd van tage. 



