with brick, a cavity being left between. A material called Hygeian Rock
Building Composition has lately been introduced, which will, I believe,
be found of great utility, and, if properly applied, should insure a dry
house. A cavity of one-half an inch is left between the outer and inner
portion of the wall, whether of brick or stone, which, as the building
rises, is run in with the material made liquid by heat; and not only is
the wall waterproofed thereby, but also greatly strengthened. It may
also be used as a damp course.

Good, dry walls are of little use without good roofs, and for a
comfortable house the roofs should not only be watertight and
weathertight, but also, if I may use the term, heat-tight. There can be
no doubt that many houses are cold and chilly, in consequence of the
rapid radiation of heat through the thin roofs, if not through thin and
badly constructed walls. Under both tiles and slates, but particularly
under the latter, there should be some non-conducting substance, such
as boarding, or felt, or pugging. Then, in cold weather heat will be
retained; in hot weather it will be excluded. Roofs should be of a
suitable pitch, so that neither rain nor snow can find its way in in
windy weather. Great care must be taken in laying gutters and flats.
With them it is important that the boarding should be well laid in
narrow widths, and in the direction of the fall; otherwise the boards
cockle and form ridges and furrows in which wet will rest, and in time
decay the metal.

After having secured a sound waterproof roof, proper provision must be
made for conveying therefrom the water which of necessity falls on it in
the form of rain. All eaves spouting should be of ample size, and the
rain water down pipes should be placed at frequent intervals and of
suitable diameter. The outlets from the eaves spouting should not be