distributed throughout the dwelling-house before anything approaching
an ideal residence can be secured. As the science of hygiene advances
it is demonstrated more and more clearly that sunlight--and even
diffused daylight--may be used as a most effective weapon against the
spread of disease. Alternations of deep gloom in the dwelling-house
with the superior light resulting from brighter weather produce many
kinds of nervous derangement, not the least deleterious of which arise
from the unnecessary strain to which the eyesight is subjected. The
promise of the future is that, through the abundance of windows
provided in the walls, roofs and porches of our dwelling-houses--but
all supplemented with shutters and blinds of various kinds--there
shall be a possibility of regulating, far more accurately than at
present, the accessibility of light from outside according to the
brightness or dulness of the day.

It is hardly to be expected that many people will build "Crystal
Palaces" in which to reside; but with the immense progress that is
being made in the construction of dwellings with iron or steel frames,
and in the adaptation of various materials so that they may serve for
building purposes in conjunction with metallic frameworks, it seems
clear that many roofs, as well as large portions of walls, will in
future be made on the composite principle, using steel and glass.
These will, to a large extent, be permanently sheltered from the
direct rays of the sun when high in the heavens, by shutters
constructed on the louvre principle so that they may admit the light
from the sky continually, but actual rays or beams of sunlight only
for a short time after sunrise and at the close of day. The ceilings,
if any are provided under the roofs, will also be glazed.

The obstacles presented in the way of such a reform in a city like
London may at first sight seem so serious as to be practically
insuperable. Long rows of three or four storied houses certainly offer
but few facilities for the admission of light through the roofs of
any but the rooms on the top floors, and yet it is in the
dwelling-houses of this type that the depression caused by gloom and
the absence of light during the hours of day are most severely felt as
a source of nervous depression. Evolution in a matter of this sort
will take place gradually and along the line of least resistance.
Portions of courts, areas and yards will be glazed over in the way
described; a