of the ordinary brickwork. Gauged arches are
composed of specially made soft bricks, which are cut and rubbed to gauges
or templates so as to form perfectly fitting voussoirs. Gauging is, of
course, equally applicable to arches and walling, as it means no more than
bringing every brick exactly to a certain form by cutting and rubbing.
Gauged brickwork is set in lime putty instead of common mortar; the
finished joints should not be more than 1/32 in. wide. To give stability
the sides of the voussoirs are gauged out hollow and grouted in Portland
cement, thus connecting each brick with the next by a joggle joint. Gauged
arches, being for the most part but a half-brick in thickness on the soffit
and not being tied by a bond to anything behind them--for behind them is
the lintel with rough discharging arch over, supporting the remaining width
of the wall--require to be executed with great care and nicety. It is a
common fault with workmen to rub the bricks thinner behind than before to
lessen the labour required to obtain a very fine face joint. This practice
tends to make the work bulge outwards; it should rather be inverted if it
be done at all, though the best work is that in which the bricks are gauged
to exactly the same thickness at the back as at the front. The same fault
occurs when a gauged arch is inserted in an old wall, on account of the
difficulty of filling up with cement the space behind the bricks.

The bond of an arch obtains its name from the arrangement of headers and
stretchers on its soffit. The under side of an arch built in English bond,
therefore, will show the same arrangement as the face of a wall built in
English bond. If the arch is in Flemish the soffit presents the same
appearance as the elevation of a wall built in that bond.

It is generally held that the building of wood into brickwork [Sidenote:
Plates.] should as far as is possible be avoided. Wall plates of wood are,
however, necessary where wood joists are used, and where these plates may
not be supported on corbels of projecting brickwork or iron they must be
let flush into the wall, taking the place of a course of bricks. They form
a uniform bed for the joists, to which easy fixing is obtained. The various
modes adopted for resting and fixing the ends of joists on walls are
treated in the article CARPENTRY.

[Illustration: FIG. 15.]

Lintels, which may be of iron, steel, plain or reinforced concrete, or
stone, are used over square-h