1. For mills. The engine must be made and proportioned according to the quantity of water required to drive the mill you would make use of. Now suppose you would make a mill on a plain place, where you will have only a pond, and a small spring of water no bigger than a quill; then you must build your mill-house thirty-six feet high, in which you may make what motions, and what sort of mills you please. By the side of which house without, may be placed your water-wheel of thirty-two, thirty-three, or thirty-four feet diameter. For the height of either house or wheel I would confine no person too exactly, but I guess that a convenient height, and no more than what is common enough. Under the wheel I would have a pond, and on the top of the house a cistern of wood lined with lead. The engine may be fixed in any corner of the mill-house, twenty, twenty-one, twenty-two feet, or more, from the level of the pond: there two boilers must be fixed, as shown you in the draught for fixing the engine; and round each of them it is convenient to have a hoop of iron, with straps coming from them to rest on the brick-work, to support and strengthen them. Your clacks and pipes in the front being supported by wood, and the vessels standing on pedestals of wood, it is convenient that the flue, or chimney, be so contrived as to draw very sharp, and the flue to circulate round both the boilers, so that you may lose no part of your strength. 2. For palaces, or the nobility’s or gentlemen’s houses, you may fix the engine in any remote or out-room, whose floor is not above twenty feet from the level of your water, and you may continue your force-pipe to the top of your house, with a convenient cistern to hold your water; into which lay the pipes which may convey the water as you want it, either for pleasure or common occasions. This way of cisterns on the top of your houses or palaces would be of singular use in case of fire, as is said before; for in every staircase a pipe may go down the corner, or behind the wainscot, so as to be no blemish even to the finest of staircases. At every floor there may be a turn-cock with a screw. At the utmost end have likewise a small leather pipe, kept well oiled in a cupboard, or cavity in your wall, which may not be seen, but on the opening some part of the wainscot, or such other contrivance as the ingenious builder shall think fit to make use of. This pipe of leather must be long enough to reach from the landing-place, or stair-head, in all rooms depending thereon. One end of this pipe has a screw to fit the cock in the other pipe, and at the other end a pipe like the nose of a pair of bellows; so that wherever, though under a bed, or the remotest part of any room in the house, the fire breaks out, or is discovered, any servant having screwed the pipe to the cock, stops the nozle with his thumb till he comes to the place where the fire is, when, taking away his thumb, he, by directing the