“I was immediately impressed by the soft white light that seemed to come from everywhere. We were standing near the entrance of a large tube. On Mars the cities are all underground and are connected together by huge oval metal tubes, from three to five hundred feet in diameter. There are monorail cars as long as our pullman trains, which glide silently and very swiftly from one city to another. The bottoms of these immense tubes are used for parks, growing foodstuffs and innumerable small manufacturing plants.
“Because of the great distances between the cities these tubes have been built only partially submerged. There are emergency air locks and bulk heads at the ends where they connect to the domes; other safety and precautionary measures are used to protect cities and tunnels in case of breakdowns or outside attack. It is these tubes which have confused the astronomers on the earth. Some believe them to be canals. There are also other theories. The shifting desert sands often cover or uncover them which leads to further confusion inasmuch as they seem to appear and disappear.”