Authentic Science Fiction Monthly, No. 67 — page 92: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AUTHENTIC SCIENCE FICTION problems have to be tackled when buildings containing air are constructed in a vacuum. For example, if internal air pressure is 10 lb. per square inch, there is a force of over half a ton over each square foot, tending to explode the building! For this and other reasons, it is extremely un- likely that the Moonbase will have much of its con- struction above ground, but will be situated in caves, or in narrow clefts below ground, in the vents of extinct vol- canoes or in artificially blasted pits. Indeed, if tunnels and caves are found or constructed, the air pressure in them would do away with the need of ““‘pit-props,” the weight of rock overhead balancing the upward push of the air. Such lunar accommodation, of course, would require one or more airlocks for entrance and exit. P. L. Sowerby has calcu- lated that, allowing for the reduction of weight on the Moon, the approximate depth of a tunnel in material of similar density to granite, sandstone, etc., which is about 150 lbs. per cubic foot on Earth, would be between 50 and 60 feet. If the material is porous, he goes on, cement plastering would be required, 91 so that the air is unable to penetrate the roof. He lists three ways in which lunar materials may be made use of in building: (i) as aggregate for use with cement in the production of concrete if small enough; (ii) as rubble walling for internal partitions and occasional external works; (iii) the largest rocks may be cut to shape for special uses, e.g. doorway lintels or floor beams. Sowerby concludes, like others who have studied these problems, that the possibility of extensive surface construc- tion is exceedingly remote, but that there are no limits to the extent of an underground base, other than those imposed by the excavating equipment available and the depth re- quirements to balance air pressure with weight of rock. While the Moonbase of a few years’ status would by no means be self-supporting, it would enable larger areas of. the lunar surface to be pros- pected. By the methods of polar explorers, rockets could drop supplies of air, food and water at points many miles distant from the base, so that expeditions from the base, using inflated, flexible, suit- ably insulated domes to sleep in, could utilise these supplies comiclooks.conn