In whirling circles now they fell, now rose,
Yet never rose nor fell.—
The motions of the heavenly bodies, in every system, bear at all times the same uniform relation to each other; these expressions, therefore, are strictly just. The first relates to the appearance, the second to the reality. Thus, while to us the sun appears to go down, to more western inhabitants of the globe he appears to rise, and while he rises to us, he is going down to the more eastern; the difference being entirely relative to the various parts of the earth. And in this the expressions of our poet are equally applicable to the Ptolemaic and Copernican systems. The ancient hypothesis which made our earth the centre of the universe, is the system adopted by Camoëns, a happiness, in the opinion of the translator, to the English Lusiad. The new system is so well known, that a poetical description of it would have been no novelty to the English reader. The other has not only that advantage in its favour: but this description is perhaps the finest and fullest that ever was given of it in poetry, that of Lucretius, l. v. being chiefly argumentative, and therefore less picturesque.
Our author studied at the university of Coimbra, where the ancient system and other doctrines of the Aristotelians then, and long afterward, prevailed.
[626] He holds His loftiest state.—Called by the old philosophers and school divines the sensorium of the Deity.
[627] These spheres behold.—According to the Peripatetics, the universe consisted of eleven spheres inclosed within each other; as Fanshaw has familiarly expressed it by a simile which he has lent our author. The first of these spheres, he says—
"Doth (as in a nest
Of boxes) all the other orbs comprise."
In their accounts of this first-mentioned, but eleventh, sphere, which they called the Empyrean, or heaven of the blest, the disciples of Aristotle, and the Arab Moors, gave loose to all the warmth of imagination. And several of the Christian fathers applied to it the descriptions of heaven which are found in the Holy Scripture.
[628] Hence motion darts its force.—This is the tenth sphere, the Primum Mobile of the ancient system. To account for the appearances of the heavens, the Peripatetics ascribed a double motion to it. While its influence drew the other orbs from east to west, they supposed it had a motion of its own from west to east. To effect this, the ponderous weight and interposition of the ninth sphere, or crystalline heaven, was necessary. The ancient astronomers observed that the stars shifted their places. This they called the motion of the crystalline heaven, expressed by our poet at the rate of one pace during two hundred solar years. The famous Arab astronomer, Abulhasan, in his Meadows of Gold, calculates the revolution of this sphere to consist of 49,000 of our years. But modern discoveries have not only corrected the calculation,{*} but have also ascertained the reason of the apparent motion of the fixed stars. The earth is not a perfect sphere; the quantity of matter is greater at the equator; hence the earth turns on her axis in a rocking motion, revolving round the axis of the ecliptic, which is called the procession of the equinoxes, and makes the stars seem to shift their places at about the rate of a degree in 72 years; according to which all the stars seem to perform one revolution in the space of 25,920 years, after which they return exactly to the same situation as at the beginning of this period. However imperfect in their calculations, the Chaldean astronomers perceived that the motions of the heavens composed one great revolution. This they called the annus magnus, which those who did not understand them mistook for a restoration of all things to their first originals.
{*} However deficient the astronomy of Abulhasan may be, it is nothing to the calculation of his prophet Mohammed, who tells his disciples, that the stars were each about the bigness of a house, and hung from the sky on chains of gold.