_Author_. Hold, my good friend, a little patience; I have dealt plainly and impartially with you about the use of your old engines: and for my engine, it will clear an old work, if full of water, as readily as your tub-gins or chain-pumps, provided the shafts are good. The method I propose to clear an old mine, if sixty feet deep, and full of water, the feeders not above two-inch bore, which is done at a very small charge after this manner; _viz_. I fix my engine on the top of the mine, and only suck and deliver a three and a quarter inch bore; as soon as we have sunk the water as far as our suction will go, which will be some twenty-two, twenty-four, or twenty-six feet deep below the surface, there I make a room fit to receive another engine, which I fix with his force-pipe to go up to the top of the pit; and when I have sunk about twenty-four or twenty-six feet more, then I fix a smaller engine of two inches bore, which, sucking twenty, and forcing forty, does your work and keeps all safe; or let your small engine be kept at work, while you remove the larger engine from the top to the middle station, and then you will have occasion for no more than two engines, the greatest of which may be removed as soon as the smaller is fixed in the lowest or proper station. And that you may be convinced of my impartiality, it is my opinion, that in gaining an old work, or sinking a new one, you use your old engines of tub or chain-pumps: this engine of mine being most proper, when you are come fairly to the bottom either of the ore or coal; for then, if you have but one lift, one station or engine-room will be sufficient. And by having two sumps or bottom cisterns, your water may, in some measure, settle in one of them in its passage to the other. So that the miners working tolerably clean, and suffering as little dead or loose coal or ore as is possible to mix with the water, you may have the water to draw only a little discoloured; for you know, as well as I, that generally the water coming from mines or coal-pits, while they work by the gins now in use, is almost clear water. _Miner_. Sir, I thank you for your candour in relation to the clearing of an old work. But supposing that our water arises thick and muddy, which you know will sometimes happen, what shall we do with your engine then?