In the mean time, the vessel, _p_, being emptied of its air, turn the handle of the regulator from you again, and the force is upon the surface of the water in _p_, which surface being only heated by the steam, it does not condense it, but the steam gravitates or presses with an elastic quality like air; still increasing its elasticity or spring, till it counterpoises, or rather exceeds the weight of the water ascending in _s_, the forcing-pipe, out of which, the water in _p_ will be immediately discharged when once gotten to the top, which takes up some time to recover that power; which having once got, and being in work, it is easy for any one that never saw the engine, after half an hour's experience, to keep a constant stream running out the full bore of the pipe, _s_; for, on the outside of the vessel, _p_, you may see how the water goes out, as well as if the vessel were transparent; for, as far as the steam continues within the vessel, so far is the vessel dry without, and so very hot, as scarce to endure the least touch of the hand; but as far as the water is, the said vessel will be cold and wet, where any water has fallen on it; which cold and moisture vanishes as fast as the steam, in its descent, takes place of the water; but if you force all the water out, the steam, or a small part thereof, going through _r_, will rattle the clack, so as to give sufficient notice to pall the handle of the regulator to you, which, at the same time, begins to force out the water from _p_, without the least alteration of the stream; only, sometimes, the stream of water will be somewhat stronger than before, if you pull the handle of the regulator before any considerable quantity of steam be gone up the clack, _r_; but it is much better to let none of the steam go off, for that is but losing so much strength, and is easily prevented, by polling the regulator some little time before the vessel forcing is quite emptied. This being done, immediately turn the cock or pipe of the cistern, _x_, on _p_, so that the water proceeding from _x_, through _y_, which is never open but when turned on _p_, or _P_; but when between them, is tight and stanch; I say, the water, falling on _p_, causes, by its coolness, the steam, which had such great force just before to its elastic power, to condense, and become a vacuum or empty apace, so that the vessel, _p_, is, by the external pressure of the atmosphere, or what is vulgarly called suction, immediately refilled, while _p_ is emptying; which being done, you push the handle of the regulator from you, and throw the force on _p_, pulling the condensing pipe over _p_, causing the steam in that vessel to condense, so that it fills, while the other empties. The labour of turning these two parts of the engine, viz. the regulator and water-cock, and attending the fire, being no more than what a boy's strength can perform for a day together, and is as easily learned as their driving of a horse in a tub-gin; yet, after all, I would have men, and those, too, the most apprehensive, employed in working of the engine, supposing them more careful than boys. The difference of this charge is not to be mentioned or accounted of, when we consider the vast profit which those who use the engine will reap by it.