first and earliest appearance, ftrikes the Eye, from the fide illumin'd by the Sun, with a thin Rim, or external Part of a Circle; but remains invisible in the other part of her Face; or undistinguishable from the Ether: And the Satellites of Jupiter are drowned from the fight, like little invifible Islands, by the Ocean of Æther they float in. So, likewife, if that infinite number of fmall Stars which now fet thick together, make the Milky Way, were placed separate, and at a distance from one another, they would perfectly efcape our fight; as numberlefs others do, which fhine in clear Nights; efpecially in the Winter Seafon. Thus, again, many nebulous Stars are now diftinctly number'd, by means of the Telescope; which has alfo actually difcovered dark Parts, Spots, and Inequalities, in that pure Fountain of Light the Sun. And, certainly, if nothing elfe, yet the Gradation obferved among the Stars in point of Light; defcending from fuch as are moft clear and bright, to fuch as are dufky and obfcure; may perfuade us, that poffibly there are Globes perfectly opaque: For, the degree from a nebulous Star to an opaque Body, feems to be lefs than from the brightest Star, to a nebulous one. Befides; the human fight is plainly limited, and deceived: For whatever is difperfed in the Heavens, that has no remarkable Magnitude, nor affords a strong and vivid Light, lies concealed from us, and alters not the face of the Heavens.

Æther.

28. And let no unfkilful Perfon be here furprized at putting the QUES- That folid TION; Whether Globes of compact Matter may hang and float in Ether? Bodies do For the Earth itfelf floats pendulous in the midft of its own foft bed, the float in the Atmosphere: And vaft Maffes of watery Clouds, and Mountains of Snow, hang in the Regions of the Air; and are thence rather precipitated, than fuffer'd to defcend, before they approach near the Earth. Whence Gilbert very well obferved, that heavy Bodies removed to a vast distance from the Earth, gradually lose their motion of Defcent; which Motion has its Origin from no other appetite of Bodies, than that of coming to and associating with the Earth, which is the Mafs of Bodies of its own Nature'. And this Motion is terminated within the Sphere of its own Activity: For as to what Men talk of a Motion to the Earth's Centre, this were to make a mere nothing have an active Virtue, and attract all things to itself; whereas one Body can never be acted upon, but by another 8.

to Suns and

29. This QUESTION, therefore, concerning opaque and folid Globes, The Stars to tho it be new, and may found harsh to vulgar Ears, fhould be received be ranged ininto our Hiftory of Philofophical Aftronomy, and coupled along with that Moons. other ancient QUESTION, hitherto undetermined; viz. Which of the Stars afford an original Light of themfelves; and which receive their Light from the Sun? The Determination of this QUESTION will range the Stars into

d For thefe, confult the Authors laft mention'd.

See the Philofoph. Tranfact. French Memoirs, Wolfus, &c.

f This is only, in other words, expreffing the Motion of Gravitation to the Earth.

Suns

8 This feems to be the fame Doctrine as Sir Ifaac Newton intends, when he endeavours to affign the Caufe of Gravity; by means of a fubtile Matter. See the Queries at the End of his Opticks.

Question

(4)

Are the fixed

Stars fo many
Fires?

Suns and Moons. To thefe two QUESTIONS fhould likewife be annexed the Enquiry into the different fubftance of the Stars, in respect of each other: For their Substance appears to be various; fome being found constantly and manifeftly reddifh; others livid, others white, others bright and fhining, others nebulous, &c ".

30. Let the fourth QUESTION be this. Are the fixed Stars actual Fires? This QUESTION requires to be prudently stated, and distinctly understood: For 'tis one thing to fay, that the fixed Stars are real Fires; and a very different one, to fay that they have all the Virtues, and produce the fame Effects as common culinary Fire. We do not here mean any notional or imaginary Fire, that retains only the Name, without having the Properties of Fire: For if our common Fire were to be placed in the The Fire of Ether, in fuch a quantity as 'tis in a fixed Star, it might produce different the fixed Stars Effects from what we find among us here below. All Natures have very different from different Virtues; not only according to their Quantity, but also their Siculinary Fire in respect of tuation, with refpect to other things. For the larger Maffes of Matter, or Bodies of the fame Nature, which are collected together, in fuch a quantity as bears fome proportion to the fum of the Universe, have certain cofinical Virtues in their Wholes, that are no way found in their Parts. Thus the Ocean, which is a huge collection of Water, ebbs and flows; but Ponds and Lakes have no Motion of this kind. So again, the whole Body of the Earth hangs pendulous; but fmall portions of the Earth drop and fall downwards. Whence the fituation of a thing is of the greatest Moment, in every respect, both in the larger and fmaller Portions thereof; by reafon of agreement, or disagreement, of the things which lie contiguous or adjacent to it1.

Situation.

In respect of
Subftance.

31. But there muft neceffarily happen a greater diverfity between the Fire of the fixed Sars, and our Fire below; because they differ not only in Situation, but fomewhat alfo in Subftance: For the ftellar Fire is pure, entire, and native; but our Fire is degenerate; and, like Vulcan thrown from The difference Heaven to Earth, proves lame with the Fall. Thus, to obferve it closebetwixt cele ly; Fire, with us, feems to be out of its own Situation; trembling, furial and cu-rounded with its Oppofites, needy, and requiring a conftant fupply of AliAnary Fire. ment to preferve it from fudden perifhing: Whereas, in the Heavens, Fire feems, in its due and natural Situation; feparated and removed from all oppofite Violence; conftant in itself; preferved by things of its own likenefs; and performing its proper Operations, free and unmolested. Patricius, therefore, had no occafion, for folving the pyramidal Form of Flame, as 'tis found among us, to feign, that the upper parts of the Stars oppofite to the Æther might be pyramidal; tho the lower parts opposite to us

are

This is done in a very agreeable, geometrical Manner, by Wolfius in his Element. Aftronom. fo far as the prefent Difcoveries reach. Thus all the Planets and Comets are made Moons to the Sun, in the folar System; and all the fixed Stars probably fhewn to be Suns, with their feveral Moons about them.

See this Doctrine more largely explained by Mr. Boyle, in his Cofmical Qualities, and Cofmical Sufpicions.

are globular: For this pyramidal figure of Flame is only accidental, and proceeds from the preffure and conftriction of the Air upon it; which thus fqueezes it from the round figure it has about its own Fewel, and gradually forms it into a Pyramid: Whence Flame becomes broad at the Basis, and fharp at the Vertex; contrary to what happens in Smoke, which appears like an inverted Pyramid; because the Air receives Smoke, but compresses Flame. Hence it fhould feem probable, that as Flame is pyramidal here below, 'tis globular abovek.

manent.

32. So likewife Flame below is a momentary Body, but in Ether per- Flame in manent and durable; and even with us, Flame might remain, and fubfift in Æther perits own Form, were it not destroy'd by the Bodies which furround it; as manifeftly appears in large Flames: For Flame fituated in the midst of, and totally furrounded by another Flame, is not destroy'd; but remains in a rapid Motion, numerically the fame, and unextinguished. The Violation of Flame begins from the fides; and thence proceeds its Suffocation. And that an internal Flame will permanently continue of a globular figure, whilst an external Flame plays and vanishes in a pyramidal one, may be experimentally demonftrated, in two Flames of different Colours!.

betwixt the

celeftial and

33. There may likewife be a great difference in the heat of the celeftial Difference and terreftrial Flame: For the celeftial plays, and fpreads itself with ease and freedom, as in its own proper Sphere; whilft the terrestrial is bound down, terrestrial burns and rages, as in a Sphere not its own: For all Fire burns the strong- Flame. er for being pent up, and imprifon'd; and even the Rays of the celestial Flame, after they arrive at more dense and stubborn Bodies, depofite their gentleness, and become more violent and scorching. Ariftotle, therefore, need not have been afraid that Heraclitus's Conflagration would fire his World, tho he had allowed the Stars to be real Fires". This QUESTION, therefore, may be received according to the Explanation here given of it. 34. The next QUESTION may be this. Do the Stars receive nourish- Question ment, increafe, diminution, generation, and extinction? 'Tis certain, that fome (5.) of the Ancients imagined, from rude and vulgar Obfervation, that the fed, and caStars were nourished, like Fire; and fed from the Waters, the Ocean, and pable of Exmoisture of the Earth; or recruited by the Vapours and Exhalations there- tinction? of: But this Notion is unworthy of being made the Subject of a QUESTION. For, as we before obferved", fuch Vapours never reach any thing near the height of the Stars; nor is their Stock, by any means, fufficient to recruit the Waters here below, refresh the Earth by Rain and Dews, and at

*See Dr. Hook's Lectures of Light paffim.

For instance, the white one of Wax, or a proper Compofition of Camphire, furrounded by the blue one of Spirit of Wine.

The Author's Experiments and Discoveries upon the Subject of Light, Fire and Flame, tho he has no where profecuted the Enquiry, as he intended, feem to lay the Foundation, whereon Dr. Hook, Mr. Boyle, and Sir Ifaac Newton have fince proceeded. See, in particular, Dr. Hook's Lectures of Light.

Are the Stars

n See above, §. 17.

VOL. II.

The Stars not

common Fire.

the fame time nourish and feed fuch vaft Numbers, and fuch huge Maffes, as the celestial Globes: whilft 'tis manifest that the Earth and the Ocean have not visibly lost of their Moisture for fo many Ages; whence there seems to be as much returned back as was raised in Vapour°.

35. Nor do the Stars require to be nourish'd after the manner of our fed after the Fire. For where Matter is loft, and wafted, fomething of the like kind manner of is fupplied and affimilated; which kind of Affimilation has its Origin in Bodies, from their being furrounded with things contrary to, or unlike, themselves: But nothing of this kind can be supposed to happen in the internal and fimilar parts of the fixed Stars; no more than in the lower parts of the Earth; which also feem not to be nourifh'd, but preserve their own substance by Identity, and not by Affimilation P. But concerning the outward parts of the Bodies of the Stars; 'tis a proper QUESTION, Whether they remain in the fame conftant Tenor, without preying upon, and Some way tinging the Ether they float in. And in this fenfe let the QuESTION be put concerning the Nutrition of the Stars 9.

Question

(6.) Whether

the

36. To the foregoing QUESTION may be properly annexed another concerning the increase or diminution of the Stars in their entire Bodies; tho The stars in there are but very few Phænomena to occafion the doubt. For first, there creafe, or di- is no Example, nor any thing of the like nature, found here below, to minish in countenance the Queftion; fince our own terraqueous Globe appears to retheir wholes? ceive no remarkable increafe or diminution in its whole; but preserves its bulk and quantity, uniformly and entire1. And tho the Stars appear to our fight, fometimes greater, and sometimes lefs, in their Bodies; yet this alteration of their fize may be owing either to their greater or less distance from the Earth, as in the Apogeés and Peregées of the Planets, or to the difpofition of the Medium. But the alteration here caused by the difpofition of the Medium is easily distinguished, because it affects the appearance of no fingle Star, but the appearance of them all equally; as we find in frosty Nights, when all the Stars feem larger on this account, that the Vapours rife more fparingly, or are more forcibly held down, than whilst the entire Atmosphere is fomewhat condenfed, and brought a little to an aqueous or cryftalline nature, which magnifies Objects".

Falfe appearances of the Stars from

the interpofition of the Clouds.

37. And if any particular Vapours fhould interpofe between a Star and the Sight, fo as to magnify that Star, which frequently and manifeftly happens in the Sun and Moon, and therefore may do the fame in the other celestial

• See this Matter confider'd by Sir Ifaac Newton, Princip. Lib. III. pag. 473. Or, see above, §. 7. and the Note thereon.

See above, §. 7. and the Note thereon.

See the Question difcuffed by Dr. Hook, in his Lectures of Light.

* See the Note upon §. 7. above.

See fome uncommon Obfervations made to this Purpose in Wolf. Element. Aftronom.

P. 594, 595.

Compare this with Sir Ifaac Newton. Princip. Lib. III. p. 467, &c. and the Modern Doctrine of Refraction. See Wolf. Elem. Aftronom. Cap. VII. De Refractione & Parallaxi Fixarum.

celeftial Globes, yet this appearance cannot deceive us, because fuch alteration of Magnitude does not continue, or follow, the Star in its Motion; but the Star foon gets clear of it, and recovers its ufual appearance. There has, however, in ancient times, and again in our own, happen'd a great and most remarkable Change and Renovation in the Planet Venus, both as to Magnitude, Colour, and Figure. Since therefore the Change which conftantly and regularly follows a Star, and revolves along with its Body, must neceffarily be in the Star itself, and not in the Medium; and fince thro a neglect of Obfervation, many things that do vifibly happen in the Heavens, may efcape us; we judge it proper to receive this part of the QUESTION into

Our HISTORY.

nerated and

diffipated?

38. The other part of the QUESTION; viz. Are the Stars generated whether and diffipated in a long feries of Ages? is of the fame kind, but countenanced Stars are geby a greater number of Phænomena; tho of one kind only. For as to all the old Stars, there is no mention made of the first appearance of any one of them, thro all the Ages of the World; excepting only that idle Story of the Arcadians about the Moon: Nor, to this day, is there any one wanting of their number. But for the Comets, which both in their Form and Motion resemble the Planets; they feem to be perfectly new Stars, whofe appearances and disappearances we have ourselves feen, as well as received from the Ancients. (1.) Some imagine thefe Comets to be spent and confumed in time; (2.) Others judge them to be rarified and refolved into Æther; (3.) others, that they only abfent themselves for a feason, and return again; and (4.) others, that they appear to us only in their Perigées, or near Approximations to the Earth, and then go back again from our fight to the higher Regions of the Heavens in their Apogées. But this entire Queftion concerning the first appearance of new Stars, we affign to that place which treats exprefly of COMETS'.

39. There remains a feventh QUESTION Concerning the Milky Way; Question viz. Whether the Milky Vay be a collection of minute Stars, or a continued (7.) Body, and part of the Ether, of a middle nature betwixt ftellar and ethereal? What is the The Opinion, that the Milky Way was an Exhalation, is long fince ex- Milky Way? ploded, to the merited Reproach of Ariftotle; who dared to impofe a tranfitory and changeable Nature, upon fo fixed and conftant a Phænomenon. And, indeed, the QUESTION, at prefent, feems to be decided by Galileo; who has divided that confused Tract of Light into diftinct and small fixed Stars. For that the Milky Way fhould not intercept the fight of the other Stars. betwixt it, does not determine the Point; nor incline the Question either way.

G 2

That Venus is horned, or has the fame Phafes as the Moon, is now commonly known, and allowed. See Wolf. Elem. Aftronom. p. 480, 481.

The Author, we fee, defigned to have treated the QUESTION of Comets; but I find it no where among his Works. He feems to have had a Forefight of the prefent Cometary, as well as Planetary Syftem: And, for the prefent Syftem of the fixed Stars, he had it in great Perfection. We observed in our Preface, that the Piece is imperfe&.