Pipe-straps.—Iron straps used mostly by pipe-fitters to fasten gas-piping in place. E. G. See Figs. [321] and [322].
Pitch.—The pitch of a board is the degree to which it has been tilted.
Plan.—A drawing showing a view of an object, looking down upon it, either on top of it (e. g. see Figs. [205] and [207]), or with the upper portion sliced off (e. g. see [Fig. 190]. This shows a plan of the log-cabin at a level of the door and windows, with the upper portion removed).
Plank.—Lumber two inches or more in thickness is known as planks or planking. Anything of less thickness is known as boards.
Plumb.—Perpendicular; vertical; true. An instrument for determining whether or not an object is plumb (see [Fig. 14], Chapter I).
Proscenium.—The front portion of a stage. The Proscenium Arch is the arch or frame extending around the front of the stage of a theatre.
Pumice Stone.—A porous rock, of extreme lightness, used for polishing metals; for smoothing the surface of wood; and for smoothing the surface of a coat of paint before applying a second coat (see Painting of Canvas Canoe, page [214]).
Pyrotechnics.—The art of making fireworks; fireworks; the composition and use of fireworks.
Quad.—An abbreviation for quadrat. A block of type-metal lower than the type, used for filling out lines, and for spacing between lines. A 2-em quad is two "ems" in width, and a 3-em quad three "ems" in width.
Quartz.—Glassy crystals, having the form of a six-sided prism, terminated at each end by a pyramid. It is colorless, or transparent, when pure, and more or less opaque and in various colors when impure.