I have a vast deal of news to tell you, said I; I yesterday told you that the moon, according to all appearances, was inhabited; but I have recollected a circumstance which would expose its inhabitants to so much danger, that I don't know whether I shall not retract my former opinion. Indeed I will not suffer you to retract it, answered she. Yesterday you prepared me to receive a visit from the inhabitants of the moon, in a few days; now you are going to refuse them a place in the creation. You shall not trifle with me in this way. You told me the moon was inhabited; I surmounted the difficulty of believing it, and now I will continue to believe it. Softly! said I; we should give but half an assent to an opinion of this nature, and reserve the other half in case we should find the opposite idea better supported. I am not contented with words, she replied; give me facts: remember your comparison of the moon with St. Dennis. But, answered I, the moon is not so similar to the earth as St. Dennis is to Paris. The sun draws out of the earth and water exhalations, which rise to a certain height in the air, collect together, and form themselves into clouds. These clouds hover about the earth in irregular shapes, sometimes shadowing one part, and sometimes another. In viewing the earth from a distance, the appearance of its surface would continually vary, because a large space of country darkened by a cloud would appear less luminous than the other parts, and as the cloud dispersed, would resume its brightness: from this cause the spots on the earth would be seen to change their places, assume different forms, and sometimes be entirely dissipated. If, then, the moon had clouds in its atmosphere, we should observe this variety of spots; but we find them always confined to the same place, which proves that the sun raises no vapours from the moon. It is then a body incomparably more solid than the earth, and its more subtile particles easily dissipated as soon as they are put in motion by the heat. The moon, therefore must be a mass of rock and marble from which no evaporation proceeds; for exhalations so naturally arise where there is water, that we cannot admit the existence of water where they are not found. What sort of beings do you think could inhabit these barren rocks; this country without water? Ah! cried she, you forget that you have assured me the seas in the moon were distinguishable. It was a mere conjecture,[26] I replied; I am sorry to have led you astray. These dark places that have been taken for seas are probably only deep cavities: at so great a distance it is excusable if we don't always guess aright. But, said she, will your objections oblige us to conclude that the moon has no inhabitants? By no means, answered I, we will neither decide one way or the other. I must own my weakness, she replied; I cannot bear to remain in suspense. I must believe something: enable me to determine; let us ascertain the existence of these