Paper roofs may be made very flat, being raised no higher than just sufficient for throwing off the water. Instead of tile, slate, or thatch, they are covered with paper, prepared by immersion in a mixture of tar and pitch. In the first place, pieces of wood called “couples,” are laid across the walls of the building, rising two inches and a half to the foot to obtain a drainage obliquity; these couples vary from two or three to six inches square, according to the size of the roof. On the couples are placed horizontal rafters, about two inches square; the distance between the couples being from five to eight feet, and between the rafters about eighteen inches; the couples are nailed to the wall plate, and the rafters to the couples. At Tew Lodge, the rafters used were young larch-trees, sawn up the middle, cut to the proper lengths, and prepared so that the upper surface should be level. On the rafters are placed thin boards, from a half to five-eighths of an inch in thickness; these boards are nailed to the rafters, not horizontally as for slating, but in a direction from the eaves to the ridge of the roof. In some cases substitutes for thin boards may be used; such as close copse-wood hurdles, plastered over; or common plaster-laths. The paper employed may be any common, coarse, strong kind; that kind used by button-makers being favourable for the purpose. It is prepared as follows: a boiler or cauldron, three feet wide by two deep, placed over a fire, is filled to within six inches of the top with tar and pitch, in the proportion of three parts of the former to one of the latter; the fire being applied and the mixture made to boil, the paper is immersed in it one sheet at a time, and then laid in a stack or pile with such a slope as to allow it to drain, a little grease of any kind being placed between the sheets to prevent their adhering; and when dry the paper is similarly treated a second time. The paper thus prepared is then nailed down to the roof. The workman begins at the eaves, and allows three inches for being turned down and nailed underneath the end of the board, which boards project an inch over the first rafter. If the paper be common, coarse, wrapping paper, it is laid on much the same as slate, so that when finished it will remain in double thickness all over the roof; but if thicker paper be employed, it is only made to overlap about three inches in each layer. Every sheet is fixed down with four nails about an inch in length, having broad flat heads.