Next morning Esmo asked me to accompany him on a visit to the seaport I have mentioned. In the course of this journey I had opportunities of learning many things respecting the social and practical conditions of human life and industry on Mars that had hitherto been unknown to me, and to appreciate the enormous advance in material civilisation which has accompanied what seems to me, as it would probably seem to any other Earth-dweller, a terrible moral degeneration. Most of these things I learned partly from my own observation, partly from the explanations of my companion; some exclusively from what he told me. We passed a house in process of building, and here I learned the manner in which the wonders of domestic architecture, which had so surprised me by their perfection and beauty, are accomplished. The material employed in all buildings 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° 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