WINDOWS
The reconstruction of the windows offers no serious difficulties,
as Carolingian windows survive in many places.
We have fashioned the windows of the Church of the Plan
after those of the basilica of Einhardt at Steinbach-in-the
Odenwald (827), the design of which has been the subject
of a special study by Walter Boeckelmann.[167]
These
windows are narrow at the outer wall surface; however, the
jambs are strongly splayed toward the inside, with steeply
slanting sills and arches. Splayed windows appear sporadically
in Roman architecture,[168]
and toward the end of the
sixth century (although not a typical feature even then), and
they were apparently common enough to attract the notice
of Gregory the Great (590-604), who expressed himself on
their virtues:
In splayed windows that portion through which the light enters is
narrow but the inner jambs which receive the light are wide. In like
manner, the minds of those who contemplate, although they perceive
the true light only weakly, are broadened internally to ample
fullness. . . . And as the windows are both open and protected, so
the hearts of those who are receptive to the grace of God will be
replenished, and yet will not permit the enemy to enter in haughtiness.[169]
In times when glass was a rare and costly commodity, the
splayed window offered the advantage of keeping the area
of glass minimal, while admitting the maximum amount of
light.