Cross-Grained

A twisted or irregular disposition of the fibres of wood, as in that part of a tree where the branches shoot from the trunk*.

Cross- Springers

In a groined ceiling, the ribs springing from the diagonals of the piers or pillars on which an arch rests.

Crown Of An Arch

Its highest point of elevation.

Cubit

A lineal measure, of different length in different nations. In ancient architecture, it was equal to the length of the arm from the elbow to the extremity of the middle finger, or about 18 in. According to Dr. Arbuth-not, the Roman cubit was 17 4-10 in.; and the Scripture cubit, a little less than 22 in. The geometrical cubit of Vitruvius was 6 ordinary cubits, or 9 ft.

Curb-Roof

A roof having two different slopes on each side. It is identical with the gambrel-roof.

Curb-Plate

A circular plate or curb, formed by scarfing two or more curved pieces together at their ends, or by uniting together pieces of plank in layers, breaking the joints as in brickwork. Curb-plates are used at the eye of domes, etc.

Curling-Stuff

Wood in which the fibres, instead of being straight, are winding, as where the branches of trees shoot from the trunk; the spiral character of the formation causing the wood to wind or curl.

Cursor

The sliding part of beam-compasses, or that part of proportional compasses by which the points are set at a given ratio.

Curve

A line that is neither straight nor composed of straight lines, but which bends continually without angles.

Curvilinear

Bounded by a curved line. Thus a roof is curvilinear when its plan is either circular or elliptical.

Cut-Roof

One that is truncated, having a flat on the top.

D

Dam

A mole, bank, or wall of earth, or a frame of wood, built to obstruct a current of water, and raise its level for driving machinery, etc.

Deal

A term more commonly used in England than in America. It denotes the wood of the fir-tree, when made into planks or boards. They are imported into England from Christiana and Dantzic, taking the names of Christiana deals and Dantzic deals. The usual thickness of the former is 3 in., and their width 9 in. Those of 1 1/4 in. thickness are called whole deals; and those of half that thickness, slit deals.

Density

A term in physics, denoting the closeness or compactness of the constituent parts of a body. In philosophy, the density of a body is the quantity of matter contained in a given bulk. Thus, if a body of equal bulk or size with another is of double the density, it contains double the quantity of matter. For example: A cubic foot of oak is more dense, and therefore contains more matter, than the same amount of pine; and a cubic foot of iron, being more dense, contains more matter than either. The weight required to crush a piece of wood is relatively as the density of the wood. A block of pine, being less dense than one of oak, is therefore more easily crushed.

Derrick

A machine used by carpenters for raising any heavy body; as the larger timbers of a frame, or sections of the frame itself.

Design

In architecture, a term denoting a plan or representation of any building. The term signifies either the general arrangement of floors, or the arrangement and disposition of the windows, doors, etc, of a building.

Details

Drawings made on a larger scale than those which simply exhibit the design of a building. They are usually of the full size of the work to be executed, and are often termed icorking-drawintrs.

Diagonal

A right line so drawn through a figure as to join the two opposite angles. Euclid used the term diameter in the same sense. In modern practice, diameter applies more properly to circular, and diagonal to angular figures.

Diagonal Scale

A measuring scale formed by horizontal lines, with diagonals drawn across them. It is designed for particularly accurate measurements.

Diameter

A right line passing through the centre of a figure, and dividing it into equal parts.

Dimension

The extent or size of a body; or length, breadth, and thickness or depth. A point has no dimensions; a line has one dimension, - namely, length; a superfice (as the side of a squared stick of timber) has two dimensions, - length and breadth; and a solid (as the whole stick) has three dimensions, - length, breadth, and thickness. The word is generally used in the plural, and denotes the whole extent of, or space occupied by, a body; as the dimensions of a room, house, or ship.

Discharge

To unload or relieve; as the removal of weight from a beam, or other timber, when too heavily loaded.

Disposition

The manner in which the several parts of a body are placed or arranged.

Dome

The spherical or other shaped convex roof over a circular or polygonal building. A segmental dome is one whose rise or elevation is less than one-half its diameter. A stilted or surmounted dome is higher than the radius of its plan or base. The oldest dome of which we are informed is that of the Pantheon at Rome, which was erected under Augustus, and is still quite perfect. In the following table will be found the dimensions of several of the principal domes of Europe. The heights are given from the ground.

Dormant Tree

A word of bad etymology, and nearly out of use It is synonymous with the terms lintel and summer.

Double Floor

A floor constructed with binding and bridg-ing joists.

Dove-Tail

A joint formed like a dove's tail: hence its name. It is made by so shaping the parts of the wood to be joined, that, when one is let into the other, it cannot be drawn out by a direct strain while its wedge-like form is retained.

Dowels

Pins of wood or iron which unite two boards or timbers in such a manner as to disguise the fastenings.