It was through this rare medium that the doctor and I learned, from day to day, something of the history of Mona’s race. The surface of the moon had once been peopled, as we supposed, but as the day of decay and death approached the outside of the globe became too inhospitable to longer support life. The interior had cooled and contracted, and as the solid crust was rigid enough to keep its place, great, sublunar caverns had been formed. Into these rushed the water and the atmosphere, accompanied by the few remaining inhabitants. The conditions were not favorable, in such places, to the continuation of the race, although their advanced knowledge in every direction prevented them from melting away suddenly. Settlements had been formed in many different sections of the moon, and interior communication was established between them. As the people gradually passed away, those who remained naturally drew nearer together until at last the remnant of the population of the globe were all gathered in the little village where we were now living. Here the process still went on, and year after year saw a constantly diminishing number. A few years before our arrival Mona’s last companion, a girl of her own age, had died, and ever since then this tuneful creature, possessed of the most sunny disposition we had ever known, had lived alone, with the knowledge that there was not another living being in all the moon. “So you see,” she sang, “I was as glad to find you as you were to hear me.” “But,” asked the doctor, “how did you know we were out there, nearly ready to be blown off into space?” “I didn’t know it till I saw you. I went out to try to discover what was the matter with my old world. For some time I had had the queerest sensations imaginable. I was accustomed to being out of doors a great deal, and I first began to notice that I could walk and run more easily than before. I was becoming rather sprightly for one who was so soon to pass off this deserted stage. Then everything I took up seemed to be growing marvelously light, and I began to have a feeling that I must hold on to all my movable possessions, to keep them from getting away. After this unaccountable state of things had existed for a while, there came, one day, a terrible shock, which threatened to crack the moon’s skull and rattle its fragments down upon my head. This was followed at intervals by similar or lighter shocks, and it was all so exceedingly unusual that I became very curious to know what was happening. Then all was quiet for many days, but when at length the quakings began again my natural instinct of self-preservation told me I ought not to take the risk of another such siege, and so I started to make my way to the surface by a well-known path. The trouble did not continue as I feared, but I kept on, fortunately for you as well as for myself, and found the outside world too uncomfortable a place for any of us to remain in longer than necessary.”