"In 1678, Prince Rupert invented a fire-place, so contrived that the draught took a downward direction before entering the flue, as shown in Fig. 18, in which... x is a wall built at a distance of 10 inches from the back of the hearth recess, and carried up to the mantel, where it is terminated by the wall x, thus completely closing all communication between the flue and the room. An opening, a, is made in this wall, 10 inches high, and of the same width as the length of the grate, and its sill is 2 inches above the top rib of the grate. Fixed within the chimney is a plate of iron, i, placed perpendicularly, so as to divide it into two equal parts. To the upper edge of this plate is hinged an iron door, c, as long as the chimney is wide, and this door can be brought into the position c, or into that indicated by the dotted lines at e. The fuel grate stands on the hearth, and is placed nearly in a line with the wall of the room. At the back of the ash-pit is a brick that closes the aperture through which the soot is removed. When the fire is first lighted, the smoke door, c, is pushed back, and when the draught is once established, this door is drawn forward, and the smoke being thus prevented from flowing upwards, reverberates downwards, and passes the lower edge of the division plate, i, and rises between it and the back of the hearth into the chimney flue. In boisterous weather, or with such a fire-place, in an upper room, where the chimney is short, another iron door, r, is hung under the edge of the mantel, in front of the fire-place, and extending the whole width of the opening. Its breadth varies according to circumstances, but it is made so as to reach within 2 inches of the upper bar of the fire-grate, when hanging in the position shown by the dotted lines at s. This converts the fire into a furnace, and the room will, in such case, be "warmer than it would be with a fire four times the size made in a common cradell." When the smoke flows regularly through the aperture, a, this door is thrown back out of use, as at r. In some cases, the ordinary fire-board or fire-cloth was used instead of this door."