COTTAGE DWELLINGS IN VARIOUS STYLES. 115 210 /^ 21 i / 212 Nine-inch brick inverted arches, fig. 210 {fg being the level of tl>e ground, and h the window or opening over the arch), are to be turned, the whole thickness of the walls, under all the external openings and chimney jambs. Inverted arches are intended to equalise the pressure of the foundations on the earth, and thus to prevent the sinking of one part more than another, or what are called settlements : it is evident that whatever carries down i i, fig. 210 must also carry down the point k. The chimney hearths, jambs (see § 79. fig. 47.), backs, breasts, and shafts, to be of brickwork. All the flues to be fourteen inches square in the clear, properly gathered (drawn in above the fireplace, till they are reduced to the proper size), and par- geted (plastered with mortar, mixed with cow- dung) ; and each flue to have a Roman cement chimney shaft (as shown by figs. 3 and 4, in the plate of details, page 118,) flanched up (sloped in "^^~-.__* --^^ a way to throw otf wet: in fig. 211, / is a section of the chimney shaft ; m, a section of the flue ; and n n, sections of the flanchings) with plam tiles set and rendered (plastered) in cement. A strong iron chimney bar (fig. 212, o o. in this figure, p is the breast; q q are the jambs ; r, the inverted arch under them ; and s, the footing, or firet course of the foundations), to be put to each of the fireplaces ; and four-inch brick trimmer arches to be turned where required. (Trimmer arches are made to support the hearth- stones, abutting at one extremity on the wall of the chimney, and at the other on trimming pieces. Trimmers are pieces of timber framed at right angles to the joists, against the ways (openings) for chimneys, and round the well-holes (openings left in floors for admitting the stair) of stairs, &c. Fig. 213 is a plan in which are seen the joists, t t; the trimming piece, u; and the fireplace, v. Fig. 214 is a section of the same plan, in I AL ^^^ 13 213 / 214 ,.^^^^^.
