Now, both from the figures of them, and from several other circumstances; these pits in the Moon seem to have been generated much after the same manner that the holes in Alabaster, and the Vulcans of the Earth are made. For first, it is not improbable, but that the substance of the Moon may be very much like that of our Earth, that is, may consist of an earthy, sandy, or rocky substance, in several of its superficial parts, which parts being agitated, undermin’d, or heav’d up, by eruptions of vapours, may naturally be thrown into the same kind of figured holes, as the small dust, or powder of Alabaster. Next, it is not improbable, but that there may be generated, within the body of the Moon, divers such kind of internal fires and heats, as may produce such Exhalations; for since we can plainly enough discover with a Telescope, that there are multitudes of such kind of eruptions in the body of the Sun it self, which is accounted the most noble Ætherial body, certainly we need not be much scandaliz’d at such kind of alterations, or corruptions, in the body of this lower and less considerable part of the universe, the Moon, which is only secundary, or attendant, on the bigger, and more considerable body of the Earth. Thirdly, ’tis not unlikely, but that supposing such a sandy or mouldring substance to be there found, and supposing also a possibility of the generation of the internal elastical body (whether you will call it air or vapours) ’tis not unlikely, I say, but that there is in the Moon a principle of gravitation, such as in the Earth. And to make this probable, I think, we need no better Argument, then the roundness, or globular Figure of the body of the Moon it self, which we may perceive very plainly by the Telescope, to be (bating the small inequality of the Hills and Vales in it, which are all of them likewise shap’d, or levelled, as it were, to answer to the center of the Moons body) perfectly of a Sphærical figure, that is, all the parts of it are so rang’d (bating the comparatively small ruggedness of the Hills and Dales) that the outmost bounds of them are equally distant from the Center of the Moon, and consequently, it is exceedingly probable also, that they are equidistant from the Center of gravitation; and indeed, the figure of the superficial parts of the Moon are so exactly shap’d, according as they should be, supposing it had a gravitating principle as the Earth has, that even the figure of those parts themselves is of sufficient efficacy to make the gravitation, and the other two suppositions probable: so that the other suppositions may be rather prov’d by this considerable Circumstance, or Observation, then this suppos’d Explication can by them; for he that shall attentively observe with an excellent Telescope, how all the Circumstances, notable in the shape of the superficial parts, are, as it were, exactly adapted to suit with such a principle, will, if he well considers the usual method of Nature in its other proceedings, find abundant argument to believe it to have really there also such a principle; for I could never observe, among all the mountainous or prominent parts of the Moon (whereof there is a huge variety) that any one part of it was plac’d in such a manner, that if there should be a gravitating, or attracting principle in the body of the Moon, it would make that part to fall, or be mov’d out of its visible posture. Next, the shape and position of the parts is such, that they all seem put into those very shapes they are in by a gravitating power: For first, there are but very few clifts, or very steep declivities in the ascent of these Mountains; for besides those Mountains, which are by Hevelius call’d the Apennine Mountains, and some other, which seem to border on the Seas of the Moon, and those only upon one side, as is common also in those Hills that are here on the Earth; there are very few that seem to have very steep ascents, but, for the most part, they are made very round, and much resemble the make of the Hills and Mountains also of the Earth; this may be partly perceived by the Hills incompassing this Vale, which I have here describ’d; and as on the Earth also, the middlemost of these Hills seems the highest, so is it obvious also, through a good Telescope, in those of the Moon; the Vales also in many are much shap’d like those of the Earth, and I am apt to think, that could we look upon the Earth from the Moon, with a good Telescope, we might easily enough perceive its surface to be very much like that of the Moon.
Now whereas in this small draught, (as there would be multitudes if the whole Moon were drawn after this manner) there are several little Ebullitions, or Dishes, even in the Vales themselves, and in the incompassing Hills also; this will, from this supposition, (which I have, I think, upon very good reason taken) be exceeding easily explicable; for, as I have several times also observ’d, in the surface of Alabaster so ordered, as I before describ’d, so may the later eruptions of vapours be even in the middle, or on the edges of the former; and other succeeding these also in time may be in the middle or edges of these, &c. of which there are Instances enough in divers parts of the body of the Moon, and by a boyling pot of Alabaster will be sufficiently exemplifi’d.
To conclude therefore, it being very probable, that the Moon has a principle of gravitation, it affords an excellent distinguishing Instance in the search after the cause of gravitation, or attraction, to hint, that it does not depend upon the diurnal or turbinated motion of the Earth, as some have somewhat inconsiderately supposed and affirmed it to do; for if the Moon has an attractive principle, whereby it is not only shap’d round, but does firmly contain and hold all its parts united, though many of them seem as loose as the sand on the Earth, and that the Moon is not mov’d about its Center; then certainly the turbination cannot be the cause of the attraction of the Earth, and therefore some other principle must be thought of, that will agree with all the secundary as well as primary Planets. But this, I confess, is but a probability, and not a demonstration, which (from any Observation yet made) it seems hardly capable of, though how successful future indeavours (promoted by the meliorating of Glasses, and observing particular circumstances) may be in this, or any other, kind, must be with patience expected.
FINIS.
THE TABLE.
Observat. [1]. Of the point of a Needle.
A Description of it: what other Bodies have the sharpest points: of the ruggedness of polisht Metal. A description of a printed point. Of very small writing, and the use of it for secret intelligence: the cause of the coursness of printed lines and points.