to no
general development upon its own unelastic lines. The real course of
development is to be traced in the gradual addition of aisles to the
church. Just as the basilica may have come into existence by the
addition of aisles to an aisleless building, so the parish church was
enlarged by the piercing of its walls for columns and arches, and the
incorporation of aisles with the main building. The usefulness of aisles
is at once apparent. They afford greater space for the distribution of
the congregation. The aisleless church may be inconveniently crowded
from wall to wall: on the other hand, where spaces are left between the
nave and side walls, the congregation will mass itself in the nave, but
the aisles will be left free until the nave is filled, and thus there
will be free access through the side doorways for as long a time as
possible. Aisles also afford a clear space for processions, and allow
them to turn inside the church at a certain point and without
difficulty. In addition to this, aisles form a convenient situation for
the smaller altars of a church, and, from an early date, were added with
this view.

Sec. 41. A parish church usually contained more than one altar, even if
served by a single priest. In the small aisleless church of Patricio in
Breconshire, in addition to the altar in the chancel, there were two
smaller altars, which still remain in place, on either side of the
central doorway of the rood screen. Such altars were dedicated in honour
of various saints; and mass would be said at them on the festivals of
those saints and on other occasions. The various popular devotions which
came into being in the middle ages, led to the multiplication of special
altars and chapels. In cathedral and abbey churches, where there were
many priests, the provision of a number of altars was, from the first, a
necessity. To this is due the adoption, from the beginning, of the
aisled plan in our larger churches, where it is a direct inheritance
from the basilican plan. At Norwich and at Gloucester, for instance, the
apse was provided with an encircling aisle, which gave access to small
apsidal chapels. The transepts also had eastern chapels ending in apses.
At Durham each transept had an eastern aisle, containing a row of such
chapels; and the abnormal development of the transepts in thirteenth
century churches, as at York, Lincoln, and Salisbury, and the occasional
provision of an eastern transept, or of a great tra