An entire body of philosophy according to the principles of the famous Renate Des Cartes in three books, (I) the institution ... (II) the history of nature ... (III) a dissertation of the want of sense and knowledge in brute animals ... / written originally in Latin by the learned Anthony Le Grand ; now carefully translated from the last corrections, alterations, and large additions of the author, never yet published ... by Richard Blome.

CHAP. XVI. How Spots come to be Generated about the Sun, and fixt Stars, and how they vanish again.

I. What the Spots of the Sun are and who was the first disco∣v••rer of them. BY the Spots of the Sun, we understand those close or compact Bodies, consisting of gross and slow Particles, mixt with others that are more Thin and Subtil, which since they cannot com∣ply with the motion of a more Sbtil matter, are cast out from it; and by reason of their slower motion, clinging together about the Surface of the Sun, continue there for some time, and follow the Suns motion, according to the course of the Eclip∣tick, till by the Suns force they be dissolved, or suckt in again by it, or wholly expell'd from it. The first Observer and Discoverer of these Spots was GALILAEUS, in the year 1610, when he was Mathematick Professor in the University of Pa∣dua; and asserted them to be contiguous to the Bo∣dy of the Sun, and that they moved round it, or rather were whirld about by the Solar Globe in the Space of 26 or 27 Days.

II. The Colour and Figure of the So∣lar Spots. The Spots of the Sun appear for the most part of a Black-colour, and are commonly surrounded with a Darkish cloud, which in the inside is more Bright than it appears on the outside. They va∣ry their Figures; as appears by that Spot which was first discovered by the Famous CASSINUS in 1672, and which appeared 36 or 37 Days. These Spots are moved more slowly from the Eastern part of the Sun, to the West, and pass from one brim to the other in about 13 Days time. Their motion is found to be more swift near the Center; and they seem to make as great way in that part in 4. Days, as they do in 9 or 10 Days when they are near the Circumference. They appear likewise bigger in the Center, but near the Circumference long and narrow. From this their swifter motion near the Center, it is concluded ei∣ther that they cling to the Sun, or at least are very near to him.

III. How these Spots are formed. Now as to the manner of their Formation we are to note, that the Particles of the first Element are not all of them of the same Bigness and Fi∣gure; and tho' we conceive them to be very Little, yet withal we must conclude some of them to be cornerd, and not so fit for motion, if we consider the Spaces or Intervals of the Globuli through which they pass: For these Spaces being mostly Triangular, they by passing through them get the same Figure, not much unlike the form of a Screw, as hath been before observed: By which means it is, that they cannot move so swiftly as before, but do as it were rest or lye still, with re∣spect to others that are more swiftly moved, and so more easily cling together. For tho' they re∣tain the name of the first Element, as long as they continue between the Globuli of the second Ele∣ment, because then being yet in their swift course, they only fill up the Spaces that are betwixt the Globuli, without composing any grosser Bodies: Yet they obtain the name of the third Element, when they come near to the Body of the Sun, es∣pecially the more gross and slowly moved Parti∣cles; for seeing they cannot comply with the mo∣tion of the rest of the subtil Matter of the first Element, they are cast out from it, and by running together into great Lumps or masses, they obscure and at last wholly hide the Star, from whence they came forth; for by clinging to its Surface, they darken and obstruct the Light proceeding from it, and hinder it from pushing forwards the subtil Mat∣ter in right Lines, wherein the force of Light doth consist.

IV. Spots are of two sorts Some Spots are more Solid, and very compact, as are those which run round the Sun; others are more thin, and therefore dissipable, such as are those which sometimes appear about the Sun, and then vanish again.

V. Spots like a kind of Scum, stick to the Star whence they pro∣ceed. For as we see that Water or Oil boyling in a pot, doth cast off those Particles that are less fit for motion, and raise them up to the Surface, redu∣cing them into Scum: So the Sun, whose matter is agitated with a fervent Heat, doth cast off from it, those grosser and many corner'd Particles, which cannot accommodate themselves to the mo∣tions of others, and these afterwards running toge∣ther, constitute a kind of Scum, and so obstruct the Light. Which then more especially happens, when the Sun darts his Rays more forceably a∣gainst them, for by this means, they are driven more closely together, and become more com∣pact.

VI. The Sun ap∣pears som••∣times more dim and obscure be∣cause of the interpositi∣on of his Spots. By this means it may happen, that a Spot which at first is Soft and very thin, may at last grow to that hardness, as to stop the passage of the Suns Rays. Thus Historians assure us, that the Sun hath been seen for many days together of a Pale colour, not much exceeding the weak and dim Light of the Moon. Neither, in my Judgment, is there any other reason assignable, why some Stars ap∣pear now greater, and at other times less, but be∣cause their Aspect is varied, according to the di∣versity of Spots that surround them: Yea, they may sometimes become so totally cover'd by them, that for many years they may be hid from us. So formerly the Constellation of the Pleiades consi∣sted of 7 Stars, whereas now 6 only can be seen.

VII. How a new Star may suddenly appear. And on the contrary it sometimes happens, that a Star not seen before, all on a sudden appears to the World: Which is when the Vortex wherein the Spot is, by pressing the Neighbouring Vortexes more strongly, than they press it, doth enlarge its Bounds; by which means the Matter of the first Element, rushing in more abundantly, to the ob∣scured Star, diffuseth it self over the Surface of the Spot; as Water is seen sometimes to over-flow the Ice: and then the Star Shines forth as Bright as if it had no Spot at all to darken it. Accord∣ing to this Hypothesis, we may understand how the New Star came to appear in Cassiopeia in the year 1572, which continued for 2 years, but

appeared greatest at first, and afterwards being darkned by Degrees, at last wholly vanished.

VIII. How these Spots are sometimes turned into Torches. It also happens sometimes, that the solar Matter flowing about the Spots wherewith it is coverd, doth rise above or beyond them, which Matter being thus pent up between them, and the Surface of the Neighbouring Heaven, is made to move more swiftly; as a River that is straitned in its passage doth run with more violence. And for this reason it is, that often Torches or bright Flames have been seen where formerly Spots appeared; and so on the contrary, the parts of Spots begin∣ning to appear again, Spots have been seen where formerly Torches appeared.

IX. Why the Spots about the Sun move so slowly. The Spots about the Sun, take up no less time than 26 Days in running round it, notwithstanding they are so near to the Body of it; which slowness of their motion proceeds chiefly from hence, that a kind of Aether is generated, of the Striate Mat∣ter which the Sun continually casts forth, which extending it self a great way towards the Orb of Mercury, doth hinder the motion of the Ma∣culae.

X. The Cause of the Darkness which hap∣ned at the Death of Christ. It doth not appear by Authors, whether the whole Earth was darkned at the Death of Christ, or the Holy Land only: But supposing (as it is most probable) that the whole Earth was obscu∣red (as the Scripture seems to assert, and Dionysius the Areopagite does plainly witness, who was a Spectator of this wonderful Eclipse at Heliopolis in Egypt) the cause of this Obscuration can▪t be attributed to any thing better than to these Spots. Seeing it is possible for one Spot to spread it self over the whole Surface of the Sun, and to con∣tinue there for some time, before it be dispers'd again. And forasmuch as the Body of the Moon is much less than that of the Sun, we must con∣clude, that this total Obscuration could not proceed from the Moon alone, without the assistance of these Solar Maculae, or Spots.

XI. The Moon assisted in the obscu∣ration of the Sun, at our Saviour's Death. I will not deny, but this famous Eclipse might be caused by the intervention of the Moons Body, not∣withstanding that it hapned at the time of the Full Moon. It appeared so to St. DENYS, as he testifies in his Epistle to Polycarpus: Whilst I was (saith he) at Heliopolis in Egypt, I beyond all expectation saw the Moon upon the Body of the Sun. Where∣upon, as being astonished at this Prodigy, he cried out, Either the God of Nature suffers, or the Frame of thus World is dissolving. But then, because the Body of the Moon was not great enough to effect a total obscuration, the Solar Spots came to its assistance, and wholly cover'd the Sun for three Hours together.

XII. How these Spots come to disap∣pear again. As these Spots are generated, so in like manner are they dissolved again and vanish. For as Oil and other Liquors, do after some time suck into themselves again the Scum that hath cover'd their Surface; so likewise the Striate Particles, that cover the face of the Sun, in process of time grow less; and as they at first came from it, so they return to the Sun again. Except the thick∣ness of the Parts, into which they are resolv'd, be such, that they are not able to pass through the Globuli, that are near the Sun; and therefore are forc'd to wander about, and disperse themselves in the adjacent Heaven.