Jack-Studs

The shorter stills in the side of a building, which are cut in under or upon the braces. etc.

Jack-Timber

Any piece of timber in the frame of a building, if cut short of its usual length, receives the epithet jack

Jamb

The side of any opening in a wall.

Jamb-Posts

The posts at the sides of a door to which the jamb-lininsrs are affixed.

Jerkin-Head

A roof the end of which is constructed in a shape intermediate between a gable and a hip: the gable being continued, as usual, up to the line of the top of the collar-beam: and, from this level, the roof is hipped, or inclined backwards. This form is rarely adopted, except in some cottages, or in decorative architecture.

Joggle

A joint so formed, that, when its parts are joined, a , force applied perpendicular to that: which holds them together will not cause them to slide past each other. A strut of a truss-roof, or a brace, when tenoned or let into the wood against it at its end. in ' any part of a building, may be said to be joggled.

Joiner

A mechanic who fin-ishes a building after it has been framed, raised, and boarded by the carpenter. The work performed by the joiner is called joinery.

Joint

The place where two surfaces meet.

Jointer

The name of the two larger planes used by joiners. They are of two lengths; thus takiug, respectively, the names of long- and short jointer.

Joists

Those smaller timbers of a building, framed into the girders and girts, to which the floor-boards are nailed, or into the plates and girts upon which is nailed the outside boarding. The term, in this country, generally denotes any piece of timber more than 2 and less than 6 in. square. It is synonymous with the old term juffers.

K

Kerf

The channel, or slit, made in wood by the teeth of a saw. The term is also used to denote the notches usually made in a stick of timber by the hewer, before he takes off the larger pieces between the kerfs.

Key

A piece of wood (usually of oak) let into another to prevent warping. It also denotes the wedge-formed pieces sometimes put into a mortise at the side of a tenon to prevent its being drawn back out of the mortise. Also those square or round pieces usually put through a scarfing to prevent its parts sliding past each other.

King-Post

In old methods of carpentry, the centre-posts in a trussed roof. This post is also known as curb-punt and prick-post.

L

Landing

That part of a floor at the termination of a flight of stairs, either at the bottom or top.

Lantern

An erection on the top of a roof or dome, having an aperture for the admission of light. Its plan may be either circular, elliptical, square, or polygonal.

Lath

Literally, a thin slip of wood. In America, the word is used almost exclusively to denote strips of wood 4 ft. long, If in. wide, and § of an in. thick, used for covering the partition-studs and furring, preparatory to plastering. Laths of this kind are cut from the refuse pieces of timber called slabs, which are the segmental pieces first cut from a log previous to sawing it into boards. etc. They are put up in bundles of a hundred each. In England, the term lath generally denotes narrow strips of wood nailed to the rafters to support the slating or tiling of a roof; also those which support plastering.

Ledgment

The development of a body as stretched out or drawn on a plane, so that the arrangement of its parts, and the dimensions of its different sides, may be readily seen and ascertained. The drawing of a roof, as seen from a point over it. is said to be a view of the same in ledcrment.

Ledgers are, in scaffolding, the horizontal pieces parallel to the walls of the building. They are nailed to the outside of the poles, and opposite the end of the brackets upon which the floors of the scaffolding are laid.

Level

A horizontal line, or plane parallel with the horizon. The term also denotes an instrument used by artisans to decide when lines or planes are of equal elevation at both ends.

Line

In geometry, a term denoting a magnitude of but one dimension, which Euclid defines to be length without breadth or thickness. The term also denotes the twelfth part of a French in. A right line is the shortest straight line that can be drawn between two given points A horizontal line is one level or parallel with the horizon. A line which is plumb leans neither way, but is at right angles with, or perpendicular to, a level line.

Lintel

A horizontal piece of timber or stone, over a door, window, or other opening, to support a superincumbent weight.

Lumber

The term in this country is usually understood to mean logs or timbers after they are cut and sawed or split for use, and applies to all descriptions and dimensions; such as beams, boards, joists, planks, shingles, etc.

M

M Roof

A roof formed of two common roofs by placing their eaves against and parallel to each other, like the letter W inverted (M). The design of the M roof is that a larger space or span may be roofed over with light timber than could safely be done were the span covered with a single pitched roof. By the use of the M roof, a saving is also made in the gable-end; the sum of the surface of the two gables of the M roof being less than in one large gable.

Mallet

A large wooden hammer used by carpenters for driving the chisel in mortising, etc.

Mansard Roof

Identical with the gambrel or curb roof. The Mansard roof was so named from its inventor, Francis Mansard, who was born at Paris in 1645. His true name was Har-douin Julius Mansart. He was an eminent architect, and was employed by Louis XIV. to build the Palace of Versailles and the Hospital of the Invalids. He died in 1708, at the age of sixty-three.