[Through all his realms. l. 105. Mr. Herschel has given a very sublime and curious account of the construction of the heavens with his discovery of some thousand nebulae, or clouds of stars; many of which are much larger collections of stars, than all those put together, which are visible to our naked eyes, added to those which form the galaxy, or milky zone, which surrounds us. He observes that in the vicinity of these clusters of stars there are proportionally fewer stars than in other parts of the heavens; and hence he concludes, that they have attracted each other, on the supposition that infinite space was at first equally sprinkled with them; as if it had at the beginning been filled with a fluid mass, which had coagulated. Mr. Herschel has further shewn, that the whole sidereal system is gradually moving round some centre, which may be an opake mass of matter, Philos. Trans. V. LXXIV. If all these Suns are moving round some great central body; they must have had a projectile force, as well as a centripetal one; and may thence be supposed to have emerged or been projected from the material, where they were produced. We can have no idea of a natural power, which could project a Sun out of Chaos, except by comparing it to the explosions or earthquakes owing to the sudden evolution of aqueous or of other more elastic vapours; of the power of which under immeasurable degrees of heat, and compression, we are yet ignorant.
It may be objected, that if the stars had been projected from a Chaos by explosions, that they must have returned again into it from the known laws of gravitation; this however would not happen, if the whole of Chaos, like grains of gunpowder, was exploded at the same time, and dispersed through infinite space at once, or in quick succession, in every possible direction. The same objection may be stated against the possibility of the planets having been thrown from the sun by explosions; and the secondary planets from the primary ones; which will be spoken of more at large in the second Canto, but if the planets are supposed to have been projected from their suns, and the secondary from the primary ones, at the beginning of their course; they might be so influenced or diverted by the attractions of the suns, or sun, in their vicinity, as to prevent their tendency to return into the body, from which they were projected.
If these innumerable and immense suns thus rising out of Chaos are supposed to have thrown out their attendant planets by new explosions, as they ascended; and those their respective satellites, filling in a moment the immensity of space with light and motion, a grander idea cannot be conceived by the mind of man.]
115 II. "ETHEREAL POWERS! YOU chase the shooting stars,
Or yoke the vollied lightenings to your cars,
Cling round the aërial bow with prisms bright,
And pleased untwist the sevenfold threads of light;
Eve's silken couch with gorgeous tints adorn,
120 And fire the arrowy throne of rising Morn.
—OR, plum'd with flame, in gay battalion's spring
To brighter regions borne on broader wing;
Where lighter gases, circumfused on high,
Form the vast concave of exterior sky;
125 With airy lens the scatter'd rays assault,
And bend the twilight round the dusky vault;
Ride, with broad eye and scintillating hair,
The rapid Fire-ball through the midnight air;
Dart from the North on pale electric streams,
130 Fringing Night's sable robe with transient beams.
—OR rein the Planets in their swift careers,
Gilding with borrow'd light their twinkling spheres;
Alarm with comet-blaze the sapphire plain,
The wan stars glimmering through its silver train;
135 Gem the bright Zodiac, stud the glowing pole,
Or give the Sun's phlogistic orb to roll.
[Chase the shooting stars. l. 115. The meteors called shooting stars, the lightening, the rainbow, and the clouds, are phenomena of the lower regions of the atmosphere. The twilight, the meteors call'd fire-balls, or flying dragons, and the northern lights, inhabit the higher regions of the atmosphere. See additional notes, No. I.]
[Cling round the aerial bow. l. 117. See additional notes, No. II]
[Eve's silken couch. l. 119. See additional notes, No. III.]
[Where lighter gases. l. 123. Mr. Cavendish has shewn that the gas called inflammable air, is at least ten times lighter than common air; Mr. Lavoisier contends, that it is one of the component parts of water, and is by him called hydrogene. It is supposed to afford their principal nourishment to vegetables and thence to animals, and is perpetually rising from their decomposition; this source of it in hot climates, and in summer months, is so great as to exceed estimation. Now if this light gas passes through the atmosphere, without combining with it, it must compose another atmosphere over the aerial one; which must expand, when the pressure above it is thus taken away, to inconceivable tenuity.
If this supernatural gasseous atmosphere floats upon the aerial one, like ether upon water, what must happen? 1. it will flow from the line, where it will be produced in the greatest quantities, and become much accumulated over the poles of the earth; 2. the common air, or lower stratum of the atmosphere, will be much thinner over the poles than at the line; because if a glass globe be filled with oil and water, and whirled upon its axis, the centrifugal power will carry the heavier fluid to the circumference, and the lighter will in consequence be found round the axis. 3. There may be a place at some certain latitude between the poles and the line on each side the equator, where the inflammable supernatant atmosphere may end, owing to the greater centrifugal force of the heavier aerial atmosphere. 4. Between the termination of the aerial and the beginning of the gasseous atmosphere, the airs will occasionally be intermixed, and thus become inflammable by the electric spark; these circumstances will assist in explaining the phenomena of fire-balls, northern lights, and of some variable winds, and long continued rains.
Since the above note was first written, Mr. Volta I am informed has applied the supposition of a supernatant atmosphere of inflammable air, to explain some phenomena in meteorology. And Mr. Lavoisier has announced his design to write on this subject. Traité de Chimie, Tom. I. I am happy to find these opinions supported by such respectable authority.]