Dimension Stone—Cut stone whose precise dimensions in a building are specified in the plans. The term refers to the highest grade of ashlar work.
Dowel—A straight bar of iron, copper, or even stone, which is inserted in two corresponding holes in adjacent stones. They may be vertical across horizontal joints, or horizontal across vertical joints, In the latter case, they are frequently used to tic the stones of a coping or cornice. The extra space between the dowels and the stones should be filled with melted lead, sulphur, or cement grout.
Draft—A line on the surface of a stone which is cut to the breadth of the draft chisel.
Dry Stone which is put in place without mortar.
upper surface of an arch.
exposed surface of a wall.
tool having a hammer face and an ax face. It is used for roughly squaring up stones, either for rubble work or in preparation for finer stone dressing. See Fig. 26.
Plugs.
foundation masonry for a wall or pier, usually composed (in stone masonry) of large stones having a sufficient area so that the pressure upon the subsoil shall not exceed a safe limit, and having sufficient transverse strength to distribute the pressure uniformly over the subsoil.
thin mixture of cement, sand, and water, which is sometimes forced by pressure into the cracks in defective masonry or to fill cavities which have formed behind masonry walls. Some times grout has been used to solidify quicksand. Its use must always be considered as a makeshift with which to improve a bad condition of affairs. It is frequently used in the endeavor to hide defective work.
stone laid with its greatest dimension perpendicular to the face of a. wall. Its purpose is to bond together the facing and the backing.
inner (or under) surface of an arch.
vertical sides of an opening left in a wall for a door or window.
horizontal and vertical spaces between the stones, which are filled with mortar, are called the joints. When they are horizontal, they are called Their width or thickness depends on the accuracy with which the stones are dressed. The joint should always have such a width that any irregularity on the surface of a stone shall not penetrate completely through the mortar joint and cause the stones to bear directly on each other, thus pro ducing concentrated pressures and transverse stresses which might rupture the stones. The criterion used by a committee of the
American Society of Civil Engineers in classifying different grades of masonry, is to make the classification depend on the required thick ness of the joint. These thicknesses have been given when defining various grades of stonemasonry.
Lintel—The stone, iron, wood, or concrete beam covering the opening left in a wall for a door or window.
Natural Bed—The surfaces of a stone parallel to its stratifi cation.
One-3I an Stone—A term used to designate roughly the size and weight of stone used in a wall. It represents, approximately, the size of stone which can be readily and continuously handled by one man.
Pick—A tool which roughly resembles an earth pick, but which has two sharp points. It is used like a cavil for roughly breaking up and forming the stones as de sired. (See Fig. 27.) Pitched-Faced Masonry—That in which the edges of the stone are dressed to form a rectangle which lies in a true plane, although the portion of the face between the edges is not plane. (See Fig. 2S.) Pitching Chisel—A tool which is used with a mallet to prepare pitched-face masonry. The usual dimensions are as illustrated in Fig. 29.
Plinth—Another term for IV ater-T able, which see.
Plug—A plug is a truncated wedge (see Fig. 30). Correspond ing with them are wedge-shaped pieces made of half-round malleable iron. A plug is used in connection with a pair of feathers to split a section of stone uniformly. A row of holes is drilled in a straight line along the surface of the stone, and a plug and pair of feathers are inserted in each hole. The plugs in succession are tapped lightly with a hammer so that the pressure produced by all the plugs is in creased as uniformly as possible. When the pressure is uniform, the stone usually splits along the line of the holes without injury to the portions split apart.