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of Jupiter, that the motion of the heavens to that planet would be apparent, and not real. Is it not therefore reasonable to think, that it is the same with that which we observe on the earth? What confirms this analogy is, that both the earth and Jupiter are flattened at the poles, which is no doubt occasioned by their rotatory motions about imaginary axes. This circumstance should, in theory, diminish the force of gravity at the equator, and that this diminution does take place is proved by experiment. Hence every thing leads to the conclusion, that the earth has really a motion about its axis, and that the diurnal motion of the heavens is merely an illusion which is produced by it; an illusion not unlike that which represents the heavens as a blue vault, to which all the stars are fixed, and the earth as a plane on which it rests.

But there is another motion of the earth, which, as we have seen, occasions the vicissitudes of the seasons, from winter to spring, summer, and autumn. The proofs of this second motion may be easily gathered from celestial appearances, in nearly the same manner as the former. For as the Sun seems to move round the earth from east to west in the space of 24 hours, which is owing to the diurnal revolution of the earth upon its axis, from west to east, so, likewise, he seems to have an annual motion in the heavens, and to rise and set continually in different parts of them; which is certainly occasioned by the daily motion of the earth in its orbit or path round the Sun, which it completes in the space of a year. On either hypothesis the appearance is the same; that is, the Sun will appear in motion, and the earth as standing still, to a spectator on the earth, whether the Sun really move round the earth at rest, or the earth move while the Sun is at rest.

To the inhabitants of any one of the planets, the mundane sphere, with the Sun, stars, and all the other planets, will, as to us, appear to move round them from east to west; and accordingly the inhabitants

of our planet, the earth, are only liable to the same delusive appearance with those of the rest. Now it is ascertained from observation, that the orbits of the planets include the Sun as the common centre of them all; but it is only the orbits of the superior planets that include the earth, which, however, is not the centre of any one of them. The earth's orbit being ascertained, by observation, to be between those of Venus and Mars, it follows that the earth must turn round the Sun; for as it lies within the orbits of the superior planets, their motion would appear unequal and irregular (on account of the earth not being in the centre), but they would never appear either stationary, or retrograde, without this supposition.Again, from the orbits and periods of the several planets about the Sun, and the Moon and satellites round the earth, Jupiter, Saturn, and the Georgian planet, it is evident that the law of gravitation is the same towards the earth, Jupiter, and Saturn, as towards the Sun; and the periodical times of the several bodies moving round each, are in the same ratio to their several distances from them. On the supposition of the earth's annual motion, her periodical time exactly suits this law, bearing such a proportion between those of Mars and Venus, as the several other bodies directed by the same law do bear; that is, the squares of the periodical times are, in all, as the cubes of the distances from the centre of their orbits.

If the earth does not move round the Sun, the Sun must move with the Moon round the earth; now, the distance of the Sun to that of the Moon is nearly 400 to 1, and the period of the Moon being about 28 days (see the article for July), the Sun's period should be, by the law above mentioned, full 600 years, whereas it is, in fact, but a single year. This con

■ It will be 13: 4003: 282: P2; that is to the square of the periodical time of the Sun; the square root of which being taken, is equal to about 220,000 days, or 600 years.

sideration was, of itself, thought of weight enough to determine the controversy between the two opinions, and to establish the motion of the earth in its orbit for

་ ever.

The masses of the Sun and several of the planets are considerably greater than that of the earth; it is therefore much more simple to make the latter revolve round the Sun, than to put the whole solar system in motion round the earth. What a complication in the heavenly, motions would the immobility of the earth suppose ! What a rapidity of motion must be given to Jupiter; to Saturn, which is ten times farther from the Sun than the earth is; and to the Georgian planet, which is double the distance of Saturn even, to make them every year revolve round us, at the same time they are revolving round the Sun! This complication, and this rapidity of motion, disappear by transferring the motion to the earth; a motion conformable to the general law, by which the small celestial bodies revolve round the large ones which are placed in their vicinity.

We may further observe that the analogy of the earth with several of the planets confirms this theory: like Jupiter, for instance, it revolves on its axis, and is accompanied by a satellite. An observer on the surface of Jupiter would conclude that the solar system was in motion round him, and the magnitude of that planet would render this illusion less improbable than for the earth. Is it, not, therefore, reasonable to imagine, that the motion of the solar system round us is likewise only an illusion?

To an inhabitant of the Sun, (if there be inhabitants on that body, which Dr. Herschel thinks not at all improbable), these bodies will appear to move from west to east: this identity in the direction indicates a motion of the earth, but that which demonstrates it is evidently the law which exists between the times of the revolutions of the planets and their distances. from the Sun. They revolve round it slower, as

their distances are greater, and in such a manner, that the squares of the periodic times are in proportion to the cubes of their mean distances. According to this remarkable law, which will perpetuate the name of Kepler, who first discovered it, the length of a revolution of the earth, supposing it in motion round the Sun, should be exactly what it is, viz. a sidereal year. Is not this an incontestible proof that the earth moves like the other planets, and is subject to the same laws? Besides, would it not be strange to suppose the terrestrial globe, which hardly subtends a visible angle at the Sun, to be immoveable amidst the other planets which are revolving round it, and that the Sun should be carried with them about the earth?

Once more, the force, which serves to retain the planets in their respective orbits round the Sun, balances the centrifugal force, by which they have a tendency to fly off. Ought it not likewise to act upon the earth? and must not the earth oppose to this action the same centrifugal force? Thus the consideration of the celestial motions, as observed from the Sun, leaves no doubt of the real motion of the earth. We shall conclude this subject with the beautiful reasoning of the immortal Milton:

When I behold this goodly frame, this world
Of heaven and earth consisting, and compute
Their magnitudes, this earth a spot, a grain,
An atom, with the firmament compared
And all her numbered stars, that seem to roll
Spaces incomprehensible (for such

Their distance argues, and their swift return
Diurnal), merely to officiate light

Round this opacous earth, this punctual spot
One day and night; in all their vast survey
Useless besides; reasoning, I oft admire
How Nature, wise and frugal, could commit
Such disproportions.

The Naturalist's Diary.

Copious dispenser of delight, bright JUNE,
All hail! the meadows smile with flowery pride,
Shed from thy lavish hand.

AMID the variety of objects with which the face of the earth is clothed, there are many which seem to exist solely for the gratification of the senses of man, and to administer delight', but which are, in reality, designed to accomplish other and more important purposes. The innumerable beautiful herbs and flowers which, at this season of the year, meet our eye in every direction, appear designed only to ornament our earth, or to gratify our sense of smelling; but, upon a more intimate acquaintance with their peculiar properties and operations, we find, that, while they contribute to embellish our gardens, they also promote the purification and renovation of the atmosphere, which becomes contaminated from various causes. The sceptic might doubtless reply, that all this might have been accomplished by the simple transpiration of vegetables and flowers, without that variety of odours with which they abound; these may contribute to our pleasure, but where is their utility? To this a satisfactory answer can be given : these various odours are designed to point out to the brute creation those herbs or flowers to which they are peculiarly attached, to lead them to those which contribute to their nourishment, and, at the same time, to shun those which are in their nature poisonous. In this instance, then, irrational animals may

1 For me kind Nature wakes her genial pow'r,
Suckles each herb, and spreads out ev'ry flow'r :
Annual for me, the grape, the rose renew
The juice nectareous, and the balmy dew.

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