In the _Chacewater Mine_, which is situated three miles south of Redruth, is one of the largest steam engines now in use; and when erected in the year 1813, was then the most powerful engine ever made. As a proof of its immense power, if it were applied as a mill, it could grind a bushel of wheat in a minute; and notwithstanding its velocity, and the complex nature of its several parts, the engineer in charge of it, can in one instant put a stop to its motion, by the mere act of turning a screw. This engine is made upon the improved system, by Bolton and Watt, and finished with much elegance. The cylinder is 66 inches in diameter; the depth of the engine shaft is 128 fathoms; from the adit to the bottom, 90 fathoms. It makes eight strokes in a minute, and at every stroke raises 108 gallons of water to the adit, and at the same time also, 60 gallons 10 fathoms high, for the purpose of condensing the steam. The quantity of coals which it consumes in 24 hours, is estimated at about eight chaldrons. About two miles from hence, in a southerly direction, are the _Consolidated Mines_, which have only lately been re-established.[52] Here are two very powerful steam engines, with cylinders 90 inches in diameter. The expenses attending the resumption of the workings of these mines, are said to have amounted to the enormous sum of nearly £70,000; but owing to the immense quantity of copper ore which has been raised, and other advantageous circumstances, the shares are now selling in London at more than £100 per cent. The monthly charges for workmen, &c. amounts to no less a sum than £7000. These mines are now under the management of Mr. Taylor and a London Company. _Huel Unity_ and the _Poldice Mines_ are also situated in this neighbourhood; the former produces copper, and the latter tin and copper. Both have been very profitable to their adventurers, and are said to have yielded them a profit of from 12 to £16,000 annually. The Poldice Mine is one of the oldest in the county, and yields a _yellowish copper ore_, a _rosin tin_, and a few stones of _galena_. In both of these, steam engines have been long erected, but they are not on so extensive a scale as those used in some of the mines above noticed. In these mines, some of the most beautiful specimens of _arseniate of copper_ and _lead_ have been discovered. _A whitish grey copper, crystallized_, in triangular and quadrangular pyramids, has also been found here.