Any piece of timber used in a vertical position to support a superincumbent weight, or to support the horizontal timbers in the frame of a building

Protractor

Aninstru-ment for laying down angles. They are usually made of brass or German silver.

Puncheon

Nearly synonymous with post. It also denotes the short studs in a partition over a door. The word puncheon properly designates an upright post or arbor in any machine which turns vertically; as a crane, for instance.

Purlins

The horizontal pieces of timber which lie on the trusses of a roof, and support the common rafters.

Q

Queen-Post

A suspension-post in a trussed roof where two posts are employed in the truss instead of one, as is the case with a truss framed with a king-post.

R

Rabbet

A recess, or channel, cut into the arris of a piece of wood. A channel cut into a plane surface is called a groove.

Radius

The semidiameter of a circle, or the length of a right line drawn from the centre to the circumference.

Rafters

The inclined timbers of a roof, which support the covering. Those forming part of a truss, and which support the purlins, are called truss-rafters. The smaller rafters to which the boards are nailed are called common rafters.

Rail

A term in architecture of many meanings, but denoting more particularly any timbers or pieces of wood, in the rougher kinds of work, lying in a horizontal position, as in fences, etc.

Relish

A term denoting the piece cut out between two tenons existing on the same piece of wood; also a piece cut from the edge of a tenon when it would be too wide if its whole width were left.

Resistance

The power or quality in a body which enables it to avoid yielding to force or external pressure of any kind, and which lessens the effect of the opposing power; as the resistance of water to the motion of a ship, or that of wood to the operation of a cutting instrument. The following table exhibits the degree of resistance to pressure in the more common kinds of woods, taking common New-Jersey freestone as the unite -

The resistance of lead by the same unit is 6 1/2; brass, 50; iron, 107.

Rib

A curved piece of wood used for supporting the lathing and plastering of a vaulted ceiling, or the boarding of a dome.

Ridge

The highest line of a roof at the angle made by the meeting of the top of the rafters. The piece of wood against which the top ends of the rafters bear is called the ridge-puce, or ridgepole.

Right Line

The shortest line that can be drawn between two given points.

Rod

The term literally signifies any thing which is long and slender, and may be used to denote either a piece of wood or metal. It denotes also a measure of length, being 16i ft.

Rolls Or Rollers

Plain cylinders of wood used in moving large timbers or other heavy materials. They are usually from 3 I to 10 in. in diameter, and from 1 to 6 ft. long. To move one end is called cutting the roller.

Roof

The exterior horizontal covering of a building.

Roofing

The general assemblage of timber and other materials which compose the roof of a building.

Rotunda

A building round on its exterior and interior, as the Pantheon at Rome. The term is often used, however, to denote any large circular room the eil-ing of which is arched like a dome. The large room beneath the great centre dome of the Capitol, at Washington, is commonly called the Rotunda.

S

Sag Or Sagging

The bending or yielding of a stick of tim-ber between the points of support when the timber lies either in a horizontal or an inclined position. Sally. A projection of any kind. In carpentry, the term de-notes the end of a piece of timber when cut to an acute angle, obliquely to the fibres of the wood. For example, the lower end, or foot, of common rafters, where they are connected with the plate; the end of a stair-carriage, etc. The outer point is called the toe and the inner point, the heel.

Saw-Pit

The pit, or excavation, over which timber is sawed. Formerly the labor was done by two persons, one standing in the pit, and the other on the top of the log. The men who performed the work were called sawyers. This work is now done by machinery; and, fortunately for the carpenter, he is now seldom called upon to render so laborious a service as that of sawing logs by the severe and slow process of hand-labor.

Scaffolding

An assemblage or structure of joists and boards, or planks, used in erecting or decorating the walls of a building. Scaffoldings are usually built by first erecting joists in a perpendicular position, at suitable distances apart, and nailing boards to the outside of them at distances of every 6 ft. in height, in a horizontal position, and parallel to the walls of the building. The joists are called stage-poles; and the horizontal boards, ledgers. At every pole, and at right angles with the ledgers, are other boards, continued in from them to the walls. The last-named pieces are called brackets. These are covered with a floor of boards, simply laid on the brackets without nailing. The word staging is often, though improperly, used among workmen for scaffolding. A kind of scaffolding is sometimes used in the erection of wooden buildings, which consists of what are termed wooden jacks; they being confined to the walls by means of a bolt, with a nut on the inside. The jacks support boards, forming a floor as in a scaffolding, with brackets and poles.

Scale

An implement for measurement. Scales are usually made on wood or metal, and are of three kinds; viz., the plain scale, the Gunter's scale, and the diagonal scale. The plain scale contains simple divisions of any required dimension. The Gunters scale is marked by various lines and numbers, by which, with the aid of a pair of dividers, many questions in arithmetic and practical geometry are readily solved: it is usually 2 ft. long and 2 in. wide. The diagonal scale is formed by dividing its width into a certain number of parts, and then drawing diagonal lines across them. By this implement, measurements may be made with great exactness. The word scale also refers to the magnitude of a drawing, map, or other object, as compared with its original.