You astonish me, cried the Marchioness: I cannot imagine the possibility of discovering mountains and abysses, from the great irregularity they cause on the surface of the globe; but how do they distinguish earth from sea? Because, answered I, the water,[24] by suffering part of the light to pass through it, and consequently reflecting less than the earth, has, at a distance, the appearance of dark spots; whilst the solid parts, by reflecting all the light, look much more brilliant. The illustrious M. Cassini, who has acquired a greater knowledge of the celestial bodies than any man in the world, discovered in the moon something which separates, then re-unites, and afterwards loses itself in a cavity. We have reason to believe, from its appearance that this is a river. In short all these different parts are now so well known to us, that they have been named after our great men. One place is called Copernicus, another Archimedes, another Gabileus. Other parts have fancy names; there is a promontory of decams, a sea of nectar, and so on; in fact our description of the moon is so particular, that if a learned man was to take a journey there, he would be in no more danger of losing himself than I should in Paris. [Footnote 24: It is proved that there is no water in the moon, but there are volcanoes; they may even be seen without a telescope, which was the case on the 7th of March, 1794. _Philos. Trans._] But, said she, I should like to have a more detailed account of the interior of the country. The gentlemen of the observatory are not able to give it you, I replied; you must make enquiry of Astolfo, who was taken to the moon by St. John. That is one of the pleasantest follies of Ariosto, I'm sure you will be amused with it. I confess it would have been better if he had not introduced in it so respectable a name as that of St. John; poets, however, will take licenses, and we may venture to excuse this, for the whole poem is dedicated to a cardinal, and one of our popes has honoured it with a particular eulogium, which in some editions is placed before the work. This is the subject of the piece: Orlando, nephew to Charlemagne, had lost his senses, because the beautiful Angelica preferred Medore to him. Astolfo, a valourous knight-errant was one day carried by his hippogriffe to the terrestial paradise, which was at the top of a very high mountain: there he met with St. John, who informed him that it was necessary, in order to cure Orlando of his madness, for them to take a journey together to the moon. Astolfo, delighted with the opportunity of seeing a new country, needed no entreaty, and in a moment the apostle and knight took their course in a chariot of fire. As Astolfo was no philosopher, he was surprised to find the moon much larger than it appeared while he was on the earth; his astonishment however increased when he saw in it rivers, lakes, mountains, towns, forests, and, what I should have been equally