Question way. Only it may, poffibly, intimate, that the Milky Way is not placed lower than the Sphere of the fixed Stars: For if it were, and a continued Body of fome Thickness, it probably would intercept the Sight. But if placed at an equal Height with the fixed Stars that feem to appear thro it; doubtless there may be Stars in the Milky Way, or in other parts of the Ether. We therefore receive this QUESTION, that the Point may be fairly decided w: 40. The QUESTIONS for determining (1.) the Number, (2.) the Magnitudes, (3.) the Figures, and (4.) the Distances of the Stars, abftracted from the Phenomena and Hiftorical Questions*, which we shall hereafter propose, are little more than fimple philofophical Problems 1. Thus, with regard to the Number of the Stars, let it be enquired, Whether there be fo many of them as there appears to be, or more? and compare them with the Catalogue carefully made by Hipparchus, and laid down in their places on the celestial Globe. For it is but a fuperficial Reafon which is offer'd for the appearance of an innumerable Multitude of latent or fkulking Stars, on clear and frofty Nights, that this Phænomenon fhould not be owing to the existence any fmaller Stars; but only to the fhining, fparkling and vibrating Motions of thofe already known. Galileo has difcovered new Nations of little Stars; not only in the Milky Way, but also in the Region of the Planets themselves. And Stars may be invifible, not only by the Smallnefs of their Bodies, but also by their Opacity; and again by their elongation and distance from the Earth. But we refer the QUESTION CONcerning the additional number of the Stars, from the generation of new ones, as we did that of their firft appearance, and disappearance, to the place where we shall treat of the COMETS". of 41. (2.) As to the Magnitude of the Stars; their apparent Magnitudes is matter of Obfervation; but their real one matter of Philofophical Enquiry. Magnitude? Let it therefore be fought, What is the real Magnitude or Dimension of each Star, either abfolutely or comparatively? For 'tis eafier to discover and demonftrate, that the Globe of the Earth is bigger than the Globe of the Moon, than that the Globe of the Moon is fo many Miles in Circumference. But let the utmoft Endeavours be used to afcertain their precife Magnitudes; and if these cannot be procured, let their comparative Magnitudes be noted. Their real Magnitudes are to be had either from Eclipfes, and their Shadows; or from the extent of their Light and other Virtues; which each Body projects and diffuses, to a greater or finaller distance, in proportion to its Magnitude: And again, from the Proportion and Symmetry of the Universe, which, by a certain Neceffity, terminate and afcertain the Limits of See Wolf. Element. Aftronom. Cap. VIII. de Stellis fixis & novis, atque Cometis. Particularly, Obfervation 36. * Obferve, that the Author calls an Account of Facts by the Name of Hiftory; which we now often call by the Name of Obfervations. ▾ But these are wanting.. 2. See above, §. 38.. of Bodies of the fame individual Nature. But no great dependance, as to the real Magnitudes of the Stars, should be had upon the Menfurations and Calculations hitherto given us by Aftronomers: For tho this has the appearance of great Care and Exactnefs, yet 'tis too licencioufly and rafhly undertaken; whence more genuine and trufty methods of Proof fhould be diligently enquired after. The Magnitudes and Distances of the Stars mutually indicate each other, by optical Proportions; tho these require to be more thoroughly fifted and difcufs'd 2. 42. (3). The Queftion concerning the Figures of the Stars may be put Question thus. Are the Stars real Globes, or Collections of Matter into a folid and (10.) What their Spherical Figure? The Stars to the Eye feem to have three different Figures; Figures? viz. (1.) one that is spherical and radiant, as the Sun. (2.) Spherical and cornuted, as the fixed Stars; and (3.) fimply spherical, as the Moon. But here the Radiancy and the Angles regard only the Sight; and the Spherical Figure only the Subftance of the Bodies themfelves. 'Tis remarkable, that among all the Stars there is none of an oblong, triangular, fquare, or other polygon Figure. And it fhould feem, as if all the larger maffes of things naturally collected themselves into Globes, for their own Preservation, and the exacter Union of their Parts b. (11.) What their 43. (4.) Lastly, What is the true Diftance of each Star in the Depth of Question the Heavens? For the fide Distances of the Planets, as well in refpect of one another, as of the fixed Stars, are governed by their Motions. And here, Distances? as we just now observed of the Magnitude of the Stars, if their exaît Diftances cannot be had, at leaft, let their respective Distances be adjusted. Thus if we do not know the true Distance of Saturn or Jupiter from the Earth; yet this we should be certain of, that Saturn is higher in the Syftem than Jupiter. But hitherto the planetary Syftem is not fettled, nor the Order of the Planets Places, above one another, abfolutely adjusted: The Dispute ftill remaining with fome, which is the higheft, Mercury or Venus? 44. The a Great Accuracy appears to be ufed by the later Aftronomers, in procuring finished Inftruments for the bufinefs of Obfervation; efpecially by Hevelius, Dr. Hook, and many others, fince the Inftitution of the Royal Obfervatories at Greenwich, Paris, &c. And upon a Collection of Obfervations made in this way it is, that Sir Ifaac Newton builds his Theory of the Moon, and the whole Solar Syftem. But, as our Author obferves of his own Time, fo ftill greater Precision is, even at prefent, required in this Matter. And,. perhaps, it were not amifs, if the Mathematical Philofophers would verify their Obferva-tions, by the due Ufe and Improvement of the phyfical Method, here laid down by the Lord Bacon: For it is highly probable, that the best ways of making Aftronomical Difcoveries, are not yet known.. It is very feldom, that fuch eminent Contrivers, and Inventors, as the Lord Bacon, Dr. Hook, and Sir Ifaac Newton appear; and yet till many fuch Genius's fhall have contributed all their Stock, Philofophy will not be perfect; junlefs Men of more flender Capacities could, as doubtlefs they might, be taught the ART OF INVENTING. See the Novum Organum paffim, and Dr. Hook's Method of improving. Natural Philofophy. According to the Modern Discoveries, the Sun, and all the Planets, and Comets, are: fpherical, or, rather, according to Sir Ifaac Newton, Spheroidical. See these Particulars adjusted by the later Aftronomers, in Wolf. Elem. Afiranom, passins 44. The Way of discovering the true Diftances of the Stars is, (1.) by their Parallaxes; (2.) by Eclipfes; (3.) by their respective Motions; and (4.) by their different apparent Magnitudes. But other Affistances are to be procured for this purpofe; and fhould be recommended to the future In-.. dustry of Mankind d. d Certainly, the Moderns have nobly profecuted this grand Enquiry: and yet we should not stand ftill, as if all were performed by Sir Ifaac Newton, who has, indeed, done Wonders; but ftill proceed, with Vigour and Alacrity, to farther Difcoveries; which himself directs, and has laid Foundations for. Great Genius's are never fatisfied with making new Discoveries in their own Perfons; but always endeavour to lead Mankind into the way themselves have trod, defiring to be outdone by Pofterity. And the greater the Soul, the more it indulges this worthy Appetite. Hence our Author, in particular, feems to have wholly bent himself upon putting all things in the direct way of Enquiry and Determination; which is a near Approximation to Discoveries, and infinitely preferable to a few imperfect Discoveries themselves; as teaching both the prefent and future Generations, what Particulars are to be chiefly regarded, and fought after, for bringing Philofophy to perfection.. SU P.. |