simplest form in the crackling of the dry leaves of laurel or ivy, when we cast them into the fire, and still more in salt, which approximates more nearly to the substance under examination. We also often observe something like this in the tallow of candles when melted, and in the windy rustle of green wood set on fire. But it is chiefly discernible in quicksilver, which is an extremely crude substance, not unlike the water of a chalybeate spring; and the force of it, if tried by the application of fire, and prevented from egress, not greatly inferior to that of gunpowder itself. Men ought, therefore, to be admonished and conjured from this example, not in their investigation of causes to catch at only one element, and so too lightly to pronounce upon them; but to look around them with caution, and rivet their contemplation more intensely and profoundly.

Of the dissimilarity of things celestial and sublunary, in regard to eternity and mutability, that it has not been proved to be true.

X.

such a prodigious interval, what operations, movements, and changes presented themselves on the face of the globe, in engines, plants, animals, and so on, which on account of their distance would not equal the bulk of the minutest straw. Now, in bodies of such immense bulk and magnitude, that by the vastness of their dimensions they can overcome the greatness of distance, and come into visibility; it is evident from certain comets, that changes take place as they move in the expanse of the heavens. I allude to those comets, which have retained a certain unvaried relation of position to the fixed stars, such as that which in our own day appeared in Cassiopea. But as respects the earth, after having penetrated into the interior recesses of it, leaving that crust and mixture of substances which composes its surface and contiguous parts, there seems to exist there also an eternal immobility, analogous to that supposed to be found in heaven. For it is beyond a doubt, that if the earth underwent changes at an extreme depth beneath its surface, the influence of such changes, even in the region we tread, would produce greater calamities than any we behold. Most

The received opinion that the universe is regu-earthquakes, certainly, and volcanic eruptions, do larly divided and discriminated by spheres, as it were, and that there is one system of heavenly and another of sublunary being, appears to have been adopted, not without rational grounds, provided the opinion is applied with proper modifieations. For there is no doubt that the regions situated beneath the lunar orb, and above it, differ in many and important respects. Yet is not that belief more certain than this other, that the bodies in both spheres have tendencies, appetencies, and motions which are common to both. We ought then to imitate the unity of nature, to discriminate those spheres rather than rend them asunder, and not break down the continuity of our contemplation. But with respect to another received opinion, that the heavenly bodies undergo no change, but that the terrestrial or elementary (as they are called) are subject to change; and that the matter of the last resembles a courtezan ever seeking the embracement of new bodies, but of the other a matron linked to one in stable and inviolable union; it seems but a popular notion, weak, and originating in appearances and superstition. This notion appears to be tottering, and without foundation, when viewed in either way. For neither does their imagined eternity consist with heaven, nor their mutability with earth. For, with respect to heaven, we cannot rest upon it as a reason for changes not happening there, that they do not emerge to our view, the view of man being prevented no less by distance of place than by tenuity of bodies. For various changes are found to take place in the air, as is evident in heat, cold, smells, sounds, which do not fall within the line of sight. Nor, again, I suppose, would the eye, if placed in the orb of the moon, descry across

not rise from a great but a very moderate depth, since they affect such an inconsiderable part of the surface. For in proportion as such visitations agitate a wider area of the earth's surface, in the same proportion we are to suppose that their bases and primitive seats enter deeper into the bowels of the earth. These earthquakes, therefore, which are greater, (in the extent of surface agitated I mean, not in violence of tremefaction,) and which but rarely happen, may be assimilated to comets of the description we have mentioned, which are also unusual. So that the proposition with which we set out remains unshaken, namely, that between heaven and earth there is no great difference as respects stability and change. But if any one is influenced to a different opinion by the regularity and seeming exactness of the motion of the heavenly bodies, we have before us the ocean, the solitary handmaid as it were of eternity, which exhibits no less unchangeable uniformity than they. Lastly, if any one shall still insist, that nevertheless it cannot be denied, but that on the surface of the globe, and the part contiguous to it, changes innumerable take place, but that in heaven it is not so, we would have him thus answered; that we do not carry the parallel through every part; and yet if we take the upper and middle regions of air (as they are termed) for a surface and exterior integument of heaven, just as among us we regard that space over which are distributed animals, plants, minerals, as a surface or outer integument of earth, we behold in both manifold reproductions and vicissitudes, in full operation. It would, therefore, seem that all the disorder, contention, and commotion of the universe, has its seat on the frontiers of heaven and earth alone. As in civi

society, it often happens in the ordinary course of | ness in heaven," it is also said that "generations things, that the borders of two adjacent kingdoms pass away, but the earth abideth for ever." And

are wasted with a perpetual succession of inroads and affrays, while the interior provinces of either kingdom enjoy continued and profound tranquillity. And none who bestows a proper attention on the subject will make an objection of religion. For it was only a heathen flourish to ascribe to a material heaven the quality of being impregnable to decay. The sacred Scriptures ascribe eternity and destructibility equally to heaven and earth, though they assign to them a different glory and an unequal reverence. For if it be recorded, that "the sun and moon bear faithful and eternal wit

that both are transitory is a doctrine contained in the same oracle of God, namely, that "heaven and earth shall pass away, but the word of the Lord will not pass away."

These things we have noted, not from any ambition of novelty in opinion, but because, not in ignorant conjecture, but instructed by examples, we foresee that these fantastical divorces, and distinctions of objects and of regions, beyond what truth admits, will prove a serious impediment to true philosophy and the contemplation of nature. W. G. G.

THE

THEORY OF THE FIRMAMENT.

BUT as so many foiling inconveniences are found to spring up on all sides, it should be deemed satisfactory if any thing can be avouched less revolting.

bodies that are simple and perfect, not of such as are compounded and imperfectly mixed,) are clearly those two bodies, air and flame. But these are to be propounded as bodies utterly heterogeneous, not, as is commonly supposed, that flame is nothing else than air set on fire. To these correspond, in the higher regions, the ethereal and sidereal nature, as, in the inferior, water and oil, and in the still deeper parts, mer

Let us, therefore, construct a scheme of the universe, according to that measure of history hitherto known to us, reserving for our future judgment all new lights, after history, and through history, our philosophy, by induction, may have reached a maturer age. But we will, in the out-cury and sulphur, and generally crude and fat set, premise some points that have reference to the matter composing the heavenly bodies, whence their motion and formation may be better understood; afterwards setting forth our thoughts and ideas of that motion itself, the chief subject under discussion.

Nature, then, in the separating of matter, seems to have drawn an impassable bar between the rare and dense, and to have assigned the globe of the earth to the order of the dense; but every thing, from the very surface of the earth, and its waters, to the utmost extremity of the firmament, to that of the rare or volatile, as it were, to twin classes of first principles, not indeed of equal but of suitable portions. Nor indeed does either the water clinging to the clouds, or the wind pent up in the earth, disarrange this natural and appropriate position of things: but this difference, between rare or volatile, and dense or tangible, is entirely primordial or essential, and is what the system of the universe chiefly has recourse to. It proceeds from a state of things the most simple possible this is from the abundance and scarceness of matter, in proportion to its extension. What belong to the order of subtile or volatile, as found here among us, (we are speaking of those

bodies, or, in other words, bodies that have a repugnance to, and such as are susceptible of, flame; (for salts are of a compounded nature, consisting of crude and at the same time also of inflammable parts.) It is now to be seen by what compact these two great families of things, air and flame, shall have occupied by far the greater part of the universe, and what are those parts they hold in the system. In air nearest to the earth, flame lives but a momentary life, and utterly perishes. But after the air has begun to be more depurate from the effluviæ of the earth and well rarefied, the nature of flame through various* adventures explores its way, and tries to take its station in the air, and after a time acquires some duration, not from succession, as with us, but in identity;† which takes place for a time in some of the feebler comets, which are in a manner of an intermediate nature between a successive and a fixed flame; the flamy nature, however, is not fixed or established, before its arrival at the body of the moon. There the flame lays down

*Per varios casus, per tot discrimina rerum, Virg. Æn. iii 208. Per varios casus tentat et experitur,' may be translated, 'after various adventurous efforts tries,' or, ‘adven

turous through many casualties tries.'
+ Identitus: quævis actio repetita.

subdued, and assimilated, so as to thoroughly endure and become subservient to the sidereal. Wherefore, from the earth to the summit of the firmament are found three genera of regions, and, as it were, three stages, as relate to the region in which flame is extinguished, the region in which flame disperses itself; moreover, to quibble about contiguity and continuity in soft and flowing bodies, would be an utter vulgarism. Nevertheless, that point should be understood, namely, that nature is accustomed to advance to spaces by gradual steps, then, of a sudden, by leaps, and to alternate this sort of process, otherwise no fabric could be formed did she always proceed by insensible degrees; for what a jump as respects the expansion of matter is there from water to air, even ever so dense or clouded, and yet these

together in position and superficies without any medium or interposing distance: nor is it a less leap as to a substantial nature, from the region of the air to the region of the moon; in like manner, a prodigious one from the firmament. Wherefore, if any one shall have taken for continuous and contiguous, not from the manner of their annexation, but from the diversity of the bodies connected, those three regions we have spoken of, they can only be held for contiguous in their limits.

its extinguishable part, and protects itself on all sides, but yet it is a flame, weak without vigour, and having little of radiation of that kind; that is, neither vivid from its own nature, nor much excited by a contrary one; neither is it sincere, but, from its composition with an ethereal substance, such as is there met with, it is stained and mixed up. And in the region of Mercury flame has not very plentifully established itself, since, by the accumulation of its whole amount, it is able to form only a small planet, and that withal labouring and struggling, like an ignis fatuus, with a great and highly disturbed diversity of fluctuating motions, and not bearing to be separated but for a small distance from the guardian protection of the sun. Moreover, after we arrive at the region of Venus, the flamy nature begins to gain strength and to wax brighter, and to be col-bodies, so different in their nature, are joined lected into a globe of a tolerable size; nevertheless, she also is the handmaid of the sun, and shudders with an abhorrence of any greater recession from him. But in the region of the sun, flame is set, as it were, on a throne, the mean being among the flames of the planets, for there it is stronger and more glittering than the flames of the fixed stars, on account of the greater restraining* influence shed all around, and the closest possible union. But flame in the region of Mars is observed to be likewise powerful, denoting by its splendour the sun's vicinity, yet existing of its But now it is time to notice, in a clear and exown proper virtue, and admitting of a separation plicit manner, the amount and nature of what this from the sun to the extent of the whole diameter our theory, relating to the substance-matters of a of the firmament. In the region of Jupiter, how-system, may establish, as also of what it may ever, flame, laying aside, in a gradual manner, give the negative to, in order that it may be mainthis emulation, appears more serene and clear, tained or overthrown. It denies that vulgar not so much from its proper nature, (as the planet opinion, that flame is air ignited, by affirming that Venus, she being more sparkling,) but from being those two bodies, air and flame, are clearly heteless moved and excited by the nature spread rogeneous, like water and oil, sulphur and meraround him ;† in which region it is probable that cury. It negatives that vacuum coacervatum held takes place, which Galileo devised, to wit, that by Gilbert, to obtain among the scattered spheres, the firmament there begins to be studded with but affirms that the spaces are filled with aerial stars, although from their minuteness invisible. or a flamy nature. It denies that the moon is an But, again, in the region of Saturn the nature of aqueous, or a dense, or a solid body, but affirms flame seems to become somewhat languid and that it is of a flamy nature, though it be gentle faint, as being both farther removed from an alli-withal, and weak, being indeed the first rudiment ance with the sun, and exhausted by the neighbouring constellated firmament. Lastly, a flamy and sidereal nature having overpowered the ethereal nature, gives a constellated firmament composed of an ethereal and sidereal nature, as the globe of the earth is of continent and waters scattered up and down on this side and that side, the ethereal substance being however overruled, * Antiperistasin: repísaσts signifies, generally, 'circumstance: but, in Athen. 1. 5, it also denotes circuitus: ai δὲ τῆς περισάσεως θύραι τὸν ἀριθμὸν ἔικοσι οὖσαι, portm, quæ in circuitu erant, viginti, &c.; therefore, the illustrious author may mean by antiperistasis,' the attractive influence of the sun opposed to, and which detains [cohibet] the

planets in their orbits.

+ Or, "from the nature spread around him being less," &c.,

according as irritata and exasperata are taken in the nominative or ablative case.

VOL. I.-53

and the last sediment of celestial flame; since flame, (according to its density,) no less than air and liquids, admits of innumerable degrees. It establishes that flame, justly and freely posited, becomes fixed and subsists, no less than air and water; nor is it a momentary thing, and only successive in its bulk, by renewal and feeding, as is the case here with us. It maintains that flame has a natural tendency to go and collect itself into globes, after the manner of an earthy nature, but not at all like air and water, which are gathered together in orbs and the interstices of globes, but never into perfect globes. It avers that the same flamy nature in the proper place, (that is) in the constellated firmament, is dispersed in infinite round atoms, but yet. in such s rt that

that twofold principle of pure air and constellation | what rate of conduct it incites and checks itself, be not put off, nor yet flame extended to the heaven and what the nature may be of those influences of heavens. It affirms that stars are real flames, which really act upon it. In our progress of unbut that the actions of flame in the heavens should folding these things, we will refer to computations in no wise be wrested into a comparison with the and tables, that beautiful mathematical dogma, actions of flame with us, most of which operate (that all motions are restrained to circles, perby casualty. It affirms that the ether interspersed fect, or eccentric, or concentric,) and that high among stars, and the stars themselves, have re- flown dictum, (that the earth is, in respect of the spective relations to air and flame, but sublimated firmament. like a point of no magnitude,) and and rectified. And thus, with respect to the sub-many more feigned discoveries of astronomers. stance of the constitution or system of the universe, some such ideas as these have suggested themselves to our mind.

But, first, we will divide the heavenly motions: some are cosmici, others, ad invicem. Those we call cosmici, which the heavenly bodies acquire from the consent not only of the heavens, but of the universe: those ad invicem, in which some heavenly bodies depend on others: and this is a true and necessary division. On the supposition, then, of the earth standing still, (for that, at present, appears to us the truer hypothesis,) it is manifest that the heavens are carried round by a diurnal motion, the measure of which motion is the space of twenty-four hours, or thereabouts; and, consequently, the revolution is from east to west, upon certain points, (which they call poles.) south and north moreover, the heavens are not whirled round movable poles, nor, back again, are the points different from those stated and this motion verily seems in harmony with universal nature, and therefore sole, except as far as

We must now speak of the motions of the heavenly bodies, on account of which we have adduced these premises. It appears reasonable to suppose that rest is not excluded from nature as to any whole, (for we are not now discoursing of small parts.) This (waiving logical and mathematical subtleties) is mainly evident from the fact, that the inciting causes, and the velocities of the heavenly motions, gradually slacken themselves, as tending to ultimate cessation, and because that, even the heavenly bodies partake of rest, hard by the poles, and becanse, if immobility be excluded the system, it is dissolved and dissipated. But, if there be a certain accumulation and mass of matter of an immovable nature, there seems no further room to doubt that it is the globe of the earth; for a dense and close cement-it admits both of decrements and declinations; ing of matter disposes toward a languid and reluctant motion; as, on the contrary, a loose unfolding of it towards a brisk and ready one. And not without reason did 'Telesius (who revived the philosophy and discussions of Parmenides in a treatise on the principle of cold,) introduce into nature, not, indeed, a co-essentiality and coupling, (which was his wish,) but, however, an affinity and agreement, to wit, on one side, of hot, shining, rare, and immovable, and, on the opposite part, of cold, dark, dense, and immovable, by placing the site of the first harmony in the heavens, of the second on the earth. But, if rest and immobility be conceded, it seems fit that we also suppose a motion without limit and to the uttermost movable, especially in natures opposed to each other. This motion is commonly rotatory, such as is generally found in the heavenly bodies; for, motion in a circle has no termination, and seems to flow from a natural desire of the body, which moves, only that it may move, and follow itself, and seek its own embraces, and excite its nature, and enjoy it, and exercise itself in its proper operation; whereas, a motion in a right line may seem a finite journeying, and a movement to a boundary of cessation or rest, and that it may attain something, and then quietly lay down its motion. Wherefore, respecting that rotatory motion, which motion is true and perennial, and commonly supposed peculiar to the heavenly bodies, we must Inquire how it equips itself in the outset, and by

according to which decrements and declinations, this motion shoots through every thing movable, and pervades all space, from the constellated firmament even to the very bowels and inmost recesses of the earth; not by any snatched or harassing course, but by perpetual consent; and that motion in the constellated firmament is perfect and entire, as well as to a just measure of time, as by a full restoration of place; but, inasmuch as that motion recedes from the summit of the heavens, insomuch does it become more imperfect, with a reference to its slowness as well as its aberration from a circular motion. And, first, we must speak distinctly of that slowness. We affirm, that the diurnal motion of Saturn is too slow to carry it round, and restore it to the same point in twenty-four hours; but that the starry firmament is carried on quicker, and outstrips Saturn by such an excess, as, in as many days as complete thirty years, would agree with a whole circuit of the heavens. The same is to be said of the rest of the planets, according to the difference of the periodic time of each planet; so that the diurnal motion of the starry firmament (in that same period, without any regard to the magnitude of the circle) is nearly by one hour swifter than the diurnal motion of the moon; for, if the moon could complete its revolution in twenty-four days, then that excess would be one whole hour; wherefore that much talked of motion, in an opposite and contrary direction, from

west to east, which is attributed as peculiar to the and more nearly resemble circles, but the inferior planets, is not true, but only apparent, from the curves more disjoined and eccentric; for, by deoutstripping of the starry firmament toward the scending more and more, there is a perpetual west, and the leaving behind of the planets departure both from that prime state of velocity towards the east, which being granted, it is evi-and that perfect circular motion, by a law of dent that the velocity of that cosmical motion, by nature nowhere interrupted. In this, however, an unperturbed law of nature, as it descends, the planets agree, (as bodies retaining much of a decreases, so that the nearer each planet ap-common nature, though in other respects differproaches the earth, the slower it moves; whereas ing,) that they have the same limits of declination. the received opinion overthrows and turns upside For neither doth Saturn return within the tropics, down that law; and by attributing a motion of nor does the moon stray beyond the tropics, (and their own to the planets, falls into the absurdity, yet we must not dismiss from our consideration that the planets, the nearer they are to the earth, what has been handed down and remarked by (which is, naturally, the place of rest,) in that some upon the wanderings of the planet Venus,) ratio have their celerity increased; which astro- but all the planets, whether superior or inferior, nomers, in the most trifling and unsuccessful after their arrival at the tropics, turn themselves, manner, attempt to excuse, by a relaxation of the and recommence a course back again, weary of force of the primum mobile. But if it seem to a lesser spiral range, such as they would have to any one a matter of wonder, that, in spaces so undergo, if they did approach nearer the poles; vast as interpose between the starry firmament and dreading that loss of motion as destructive and the moon, that motion should gradually de- of their nature. For, howsoever it may be, in the crease by portions so small, by less, to wit, than starry firmament, both the stars near the poles, one hour, which is the twenty-fourth part of the and those about the equinoctial, preserve their diurnal motion; it subsides when we consider ranks and positions, reduced into order, one by that each planet, the nearer it is to the earth, another, with steadfastness and consummate unicompletes lesser circles, revolving in a shorter formity; nevertheless, the planets seem to be of circuit; so that, the decrement of the size of the that mixed nature, that they admit not willingly circle being added to the decrement of the period- an ampler circuit, nor bear at all a shorter. ic time, that motion is perceived to decrease in Furthermore, these doctrines concerning the heaa marked manner. Up to this time we have venly motions seem to us somewhat preferable to spoken of the velocity, absolutely and apart, as forced and opposite motions, and of a different if the planets, placed, for example, in the plane polarity of the zodiac, and an inverted order of of the equator, or of any of its parallels, were velocity, and such like, which in no way agree simply overtaken by the starry firmament, and with the nature of things, though they may in a by one another, but yet in that selfsame circle; manner accord with calculations. Neither have for this would be a mere leaving behind, without eminent astronomers been blind to these matters, any respect to obliquity. But it is manifest, that but, wrapped up in their craft, and reveries the planets not only hasten on their course with of perfect circles, catching at subtleties and the unequal relative speed, but do not return to the evil results of a fashionable philosophy, they same point of a circle, but decline towards the have disdained to follow nature. Truly, howsouth and the north, the limits of which declina-ever, is that despotic decretal against nature of tion are the tropics; which declination has pro- wise men more mischievous, than the very duced a circle oblique to us, and its different simplicity and utter credulity of the uninformed, polarity; after the same manner that that ine- when any one, for instance, looks with scorn at quality of velocity has caused the motion of an truth, because it is manifest. And yet huge is opposite action. Nor really is there need of this that evil, and most widely extended, that the figment in the nature of things, since, by introduc- human intellect, whenever it finds itself unequal ing spiral lines, (the thing that comes nearest to to subjects, has a predilection to soar above sense and fact,) the matter in dispute may be them. settled, and those points be safe and sound. Besides, (which is the sum and substance of the matter,) these spirals are nothing else than deviations from a perfectly circular motion, which the planets cannot bear; for in proportion as the substances degenerate in purity and expansion, so also do their motions. But it happens, that as in point of celerity the higher planets are carried on quicker, and the inferior slower; so, also, that the superior planets form spires that approximate*

* Propiores, if not misprinted for propriores, must respect the foci of the ellipses; which explains "disjunctas;" but,

But now we must inquire whether that one and simple motion in a circle, and in a spiral curve, from east to west, upon certain south and north poles, cease and terminate with the heavens, or it also be conveyed down to things beneath. For it would not be ingenuous in us to feign here in this nether region such aphorism as they suppose with respect to the heavens. Wherefore, if in these regions he also found that motion, it

if the illustrious author did write propiores, why did he afterwards tautologize by saying "quæque circulos propius refu rant ››