ldings is originally liquid, or rather
viscous. In the first place, the foundation is excavated to a depth of
two or three feet, the ground beaten hard, and the liquid concrete
poured into the level tank thus formed. When this has hardened
sufficiently to admit of their erection, thin frames of metal are
erected, enclosing the spaces to be occupied by the several outer and
interior walls.

These spaces are filled with the concrete at a temperature of about
80 deg. C. The tracery and the bas-reliefs impressed on the walls are
obtained by means of patterns embossed or marked upon thinner sheets
placed inside the metallic frames. The hardening is effected partly by
sudden cooling, partly by the application of electricity under great
hydraulic pressure. The flat roof is constructed in the same manner,
the whole mass, when the fluid concrete is solidified, being simply
one continuous stone, as hard and cohesive as granite. Where a flat
roof would be liable to give way or break from its own weight, the
arch or dome is employed to give the required strength, and
consequently all the largest Martial buildings are constructed in the
form of vaults or domes. As regards the form of the building,
individual or public taste is absolutely free, it being just as easy
to construct a circular or octagonal as a rectangular house or
chamber; but the latter form is almost exclusively employed for
private dwellings. The jewel-like lustre and brilliancy I have
described are given to the surfaces of the walls by the simultaneous
action of cold, electricity, and pressure, the principle of which Esmo
could not so explain as to render it intelligible to me. Almost the
whole physical labour is done by machinery, from the digging and
mixing of the materials to their conveyance and delivery into the
place prepared for them by the erection of the metallic frames, and
from the erection to the removal of the latter. The translucent
material for the windows I have described is prepared by a separate
process, and in distinct factories, and, ready hardened and cut into
sheets of the required size, is brought to the building and fixed in
its place by machinery. It can be tinted to the taste of the
purchaser; but, as a rule, a tintless crystal is preferred. The entire
work of building a large house, from the foundation to the finishing
and removal of the metallic frames, occupies from half-a-dozen to
eighteen workmen from four to eight days. This, like mo