s
(Figs. 14 and 15), and a few of earlier date. In those parts of
England where tiles are manufactured such framework was often covered
by tiles instead of being filled in with plastering. In half-timbered
houses, the fire-places and chimneys, and sometimes also the basement
storeys, are usually of brickwork or masonry; so are the side walls in
the case of houses in streets. It was usual in such buildings to cause
the upper storeys to overhang the lower ones.

_Columns and Piers._

The columns and piers of a building virtually form portions of its
walls, so far as aiding to support the weight of the roof is
concerned, and are appropriately considered in connection with them.
In Gothic architecture very little use is made of columns on the
outside of a building, and the porticoes and external rows of columns
proper to the classic styles are quite unknown. On the other hand the
series of piers, or columns, from which spring the arches which
separate the central avenues of nave, transepts and choir from the
aisles, are among the most prominent features in every church. These
piers varied in each century.[14]

The Norman piers had been frequently circular or polygonal, but
sometimes nearly square, and usually of enormous mass. Thus, at Durham
(Norman), oblong piers of about eleven feet in diameter occur
alternately with round ones of about seven feet. In transitional
examples columns of more slender proportions were employed either (as
in the choir of Canterbury) as single shafts or collected into groups.
Where grouping took place it was intended that each shaft of the group
should be seen to support some definite feature of the superincumbent
structure, as where a separate group of mouldings springs from each
shaft in a doorway, and this principle was very steadily adhered to
during the greater part of the Gothic period.[14]

[Illustration: FIG. 15.--HOUSES AT LISIEUX, FRANCE. (16TH CENTURY.)]

Through the E. E. period groups of shafts are generally employed; they
are often formed of detached shafts clustering round a central one,
and held together at intervals by bands or belts of masonry, and
generally the entire group is nearly circular on plan. In the
succeeding century (Dec. period) the piers also take the form of
groups of shafts, but they are generally carved out of one block of
stone, and the ordinary arrangement of the pier is on a lozenge-shaped
plan. In the Perp., the piers retain the same general char