Page xix

                     INTRODUCTION
ROOMS may be decorated in two ways: by a superficial ap-
     plication of ornament totally independent of structure, or by
means of those architectural features which are part of the organ-
ism of every house, inside as well as out.
  In the middle ages, when warfare and brigandage shaped the
conditions of life, and men camped in their castles much as they
did in their tents, it was natural that decorations should be porta-
ble, and that the naked walls of the medi~val chamber should be
hung with arras, while a ciel, or ceiling, of cloth stretched across
the open timbers of its roof.
  When life became more secure, and when the Italian conquests
of the Valois had acquainted men north of the Alps with the spirit
of classic tradition, proportion and the relation of voids to masses
gradually came to be regarded as the chief decorative values of the
interior.  Portable hangings were in consequence replaced by
architectural ornament: in other words, the architecture of the
room became its decoration.
  This architectural treatment held its own through every change
of taste until the second quarter of the present century; but since
then various influences have combined to sever the natural con-
nection between the outside of the modern house and its interior.
In the average house the architect's task seems virtually confined
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