The Roughness on her broken Edge reveals, Her Surface mafk'd with Vales, and pointed Hills. Her brighter Parts, the Sage mountaineous deems; Her darker, Oceans, Seas, and ample Streams. Euphrof. Well, I give you my Word, Cleonicus, if you fay much more, I fhall scarce forbear wifhing myself there, to view the vaft Countries; to fee what Sort of People inhabit them; to obferve their various Animals, their Trees, and Plants, their Arts and Sciences, their Seafons and Weather; for all thofe Things, I prefume, you allow are there as well as here. Cleon. Moft Philofophers do allow it, but fome deny the dark Parts to be Seas, and fay they are either Vales and deep Caverns, or elfe Land, of fuch a Mould as will not reflect Light enough to make it look bright like the Reft. They alfo deny there is any Atmosphere, or Body of Air about the Moon, and therefore no Vapours or Rain, &c. Euphrof. Indeed, Cleonicus: Pray, if there be no Air, how do the Inhabitants and Animals live? and if no Rain, how do Trees and Plants grow? Cleon. I can't tell what Anfwer they would make to fuch Queries. Sure I am, that Animals and Vegetables like ours, cannot live or grow where there is no Air nor Rain; and therefore they must be either different from ours, or none at all; which Suppofition will make the glorious Orb of the Moon of very little Confequence to us, and none at all to itself; an huge, but uninhabited Wild of barren Hills and gloomy Vales: A Notion of it quite unworthy its Maker. Euphrof. The Philofophers then, I find, are not agreed what Kind of Entertainment the Moon will afford one, and 'till they are, I fhall wave all Thoughts of going thither. The next Thing I would require of you, is how it comes to pafs, the Moon every Month puts on fuch a Variety of Phafes, appearing now full, now halved, then borned, and not at all when new?But I recollect myself; you explained thefe Appearances in the Planet Venus, and thofe of the Moon, I prefume, happen after the fame Manner. Cleon. They do; but it will be worth while to be a little more particular in explaining the lunar Phafes, 2 You'll You'll eafily conceive the Reafon of them from this little Scheme; where you fee the large Sun darting forth hist Beams, which, at the vast Distance of the Earth and Moon, fall nearly parallel on them. T is the Earth, and A, B, C, D, E, F, G, H, the Moon in feveral Parts of its Orbit circling round it. Here firft you obferve, that Half of the Earth and Moon, which is towards the Sun, is wholly enlightened by it, and the other Half, which is turned from it, is totally dark. Euphrof. This I apprehend very well, it being evident from the Figure. Cleon. Confequently the Moon, when it is in the Pofition A, that is, in Conjunction, or exactly between the Earth and Sun, will have all her enlightened Part turned towards the Sun, and all her dark Part towards the Earth, in which Case we cannot fee her, and is therefore said to be a new Moon. Euphrof. I take you very well; pray go on. Cleon. When the Moon has gone from A to B, then in that Half, bac, which is turned to the Earth, a fmall Portion of her Surface is enlightened, as a b, and will appear of the Form reprefented at B, in the other Scheme, (fee Plate XIII.) which fhews you the Phafes of the Moon, Euphrof. Very good; and now, Cleonicus, I fuppose you fay the Moon is horned, from the Figure she makes; do you not? Cleon. Yes, my Euphrofyne, fhe is then faid to be borned or corniculated, which is all one; but he becomes gradually lefs and lefs fo as the approaches to C, in which Situation fhe is faid to be in her Quadrature, or Square to the Sun; and then one Half of that Part towards the Earth is enlightened, and appears as at C among the Phafes. She is now faid to be dichotomized, bifected, or a Half Moon. Euphrof. And thus when he comes to D, I fee the greatest Part of that Half towards us is enlightened, and appears of the fame Face as at D in this other Scheme; and what Name have you for it then, pray? Cleon. She is then faid to be gibbous; and this Phase or Afpect increases till fhe comes to the Situation E, where he is in Oppofition to the Sun, and confequently turns turns all her illuminated Surface to the Earth, and fhines with a full Face, as you now behold her; for which Reafon fhe is called a Full Moon. Euphrof. All this I conceive perfectly well from the Schemes; and alfo I fee that as the paffes the other Half of her Orbit, from E by F, G, and H to A again, fhe puts on the fame Faces as before, but in a contrary Order and Pofition. Cleon. Very good, Sifter'; I fee you have a right Notion of the Matter, and need nothing further to be faid on this Head. I doubt not alfo, but you will eafily conceive that when fhe is new, and feen in the fame Part of the Heavens with the Sun, fhe muft needs rise and set with the Sun; as on the contrary, when he is at E, a full Moon being exactly in an oppofite Part of the Heavens to the Sun, the muft then rife when the Sun fets, and fet when he rifes. Euphrof. Yes, this I eafily understand; but am at a Lofs to know the Time of her Rifing and Setting in any other Situation. Cleon. No Wonder if you are, fince it is always variable; but this much you may know, that all the while the Moon is paffing from A by C to E, fhe is to the Eaft of the Sun, and rifcs and fets after him; but in going from E, by G, to A, fhe is Weft of the Sun, and rifes and fets before him: Always fhining fuch a Part of the Night as is proportional to the illuminated Part of her Surface towards us. Euphrof. Dear Brother, I am pleafed when I can get but a general Idea of Things; to know but fomething is infinitely more fatisfactory than abfolute Ignorance.— But the Night is far advanced, pray anfwer me one or two Questions more very briefly: Is not that a reflected Light with which the Moon fhines thus pleafantly? Cleon. It is; and therefore fo exceeding weak and languid, in Comparifon of the Sun's Light, that the greatest Burning-Glafs will not collect enough to make a fenfible Warmth.And those who have made the Computation, fay, the Full-moon Light compared with Day Light is ninety thousand Times lefs than it. Of the full Moon, and her borrowed Light, thus Mr. Baker. When |