In continuation of our discussion of the canal question, I asked Tellurio "Whether the canals and irrigation system had been the means of reclaiming any large areas of land which had previously been deserts?"
"Oh yes, sir," he answered, "that has been the case in many parts of our world; some very large areas indeed which were once deserts have now become very fertile. Quite apart from such reclamations, however, our canals and irrigation systems have also effectually checked the spread of desertism. If it had remained unchecked, probably by this time the entire surface of our planet would have become a desert."
I then explained that I asked the question because our observers had seen and noted upon their charts several large areas which seemed to have become fertile. Thus, along the eastern side of Thaumasia it had been noted that, during a period of about twenty-three years, the green area had advanced at least 400 miles nearer to the place we called the "Solar Lake." On measuring this area on the map it appeared to me that at least 200,000 square miles which had previously been desert had become fertile.
Similar extensions of vegetation had also been charted in several other places, for instance, on the east side of the large area known to us as "Syrtis Major." I had, however, been rather surprised not to have come across any comment by our scientists on the significance of this very large increase of fertile land, as, taken in connection with the great canal system, it seemed to me very significant and full of meaning.
Merna, continuing his remarks, then said that "Lately considerable extensions of their canal system had been carried out. New canals had been dug, others altered or extended, and vast areas had been considerably changed by replanting in some places and fallowing in others. The result of all this work," he said, "would produce a striking alteration in the configuration of some of the dark areas. Such changes," he remarked, "were carried out very rapidly, so rapidly indeed that it would probably be almost incredible to terrestrials; but it must be remembered that excavation, loading and removal of soil, as well as most other operations, were accomplished by special machinery. He had no doubt these changes would be noted by our observers, as Mars was so favourably situated in regard to the earth at the present time. Besides this," he continued, "many of our canals have been dealt with, and some of them will disappear, either temporarily or permanently."