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another Thing you have not considered, and that is, that the Days and Nights there are a Fortnight long each, and such tedious Intervals of Light and Darkness will not agree with your Constitution. You will, therefore, with more Pleasure imagine all these Things, than go thither to enjoy them.
Euphrof. Truly you have cured my Curiosity fufficiently, and I shall be content for the future to stay at my terrestrial Home. However, I cannot help wishing, after all, that it may be some Part of our future Happiness to visit the distant Planets of the System, and even the planetary Worlds of other Systems beyond this.But enough of this at present; what will be the Subject of our next Speculation ?
Cleon. As we are confined to the Globe of our Earth, we shall find many Subjects of Enquiry, and well suited to gratify a rational Mind, relative to the several Phænomena observable in it alone. And it is proper, that we should understand them first, which will be sufficient for the short space of Time allotted to human Life. Among these, the Seasons of the Year are what I shall next explain to you on the Orrery.
DIALOGUE IX. The Seasons of the Year explained by the ORRERY:
And First the SPRING
told me our next Business with the Orrery would be to explain the Nature of the SEASONS, and the Manner how they happen by it.
Cleon. I did so, my Euphrofyne ; and I intend it for the Subject of your Entertainment this Afternoon, if you think fit, and are at Leisure.
Euphrof. Very much so; and am impatient of lofing one Moment of Time 'till I am made sensible in some Measure of the Reason and Cause of such an agreeable Variety and
Succession Succession of Seasons which constitute the Year. Por though no one is more sensible of Heat and Cold, or more affected with the Pleasure and Beauties of the Spring, or the heavy and ill-boading Aspect of Autumn ; yet I have never been so rational as to enquire into the Causes thereof, as if I were no more concerned to know them than the Quadrupedes.
Cleon. This ingenious Reflection on yourself, Euphrosyne, is but too just a Satire on the Generality of Mankind, to whom a moderate Pursuit of any kind of Knowledge, in the Sciences, is thought but too irksome. The Seasons are the most obvious Parts of Nature, nor are they difficult to be understood by Means of the Orrery, as you will see,
-Ovid has made a fine poetical Comparison between the four Seasons the Year, and the four different States of a Man's Life in these Verses.
Perceiv'At thou not the Process of the Year :
DRYDEN's Ovid's Met. L. xv.
Euphrof. That is a very beautiful Description of the Seasons, and the Similitude seems very just and natural,
But now for a little Philosophy; pray let me see, by the Orrery, how those different Seasons are brought about in Nature.
Cleon. I will, immediately; but, previous thereto, you must observe, and get a tolerable good Notion of the following Particulars First, That the Motion of the Earth is in the Plane of the Ecliptic; that therefore Secondly, the Sun-beams are always perpendicular to that Part of the Earth which lies under the Degree of the Ecliptic in which the Sun appears at any Time.Thirdly, That the Axis of the Earth is not perpendicular to the Plane of the Ecliptic, but inclined thereto in an Angle of 66' 1; as I shewed you in the Sphere.--- Fourthly, That the Axis of the Earth keeps always in a parallel Position, or points always towards the same Parts of the Heavens, throughout its whole annual Course.--Fifthly, That the Sun being at so vast a Distance, the Rays which fall on the Earth may be looked upon as parallel among themselves : And, Sixthly, That only one half of a Globe can be enlightened at once by parallel Rays.--Do you think you understand me aright?
Euphrof. I believe I do pretty well, by what you have before taught me; and the Manner in which you now indicate these Things.
Cleon. Well then, since the SPRING is the most delightful and primary Season of the Year, we will begin with it; to represent which, you fee, I place the Earth in the Beginning of Libra -, and then the Sun will appear in the Beginning of Aries r, which being the Equinoctial Point, the Sun must for that Day equally enlighten all Places on the Earth, from Pole to Pole; and to make this Affair as clear to the Eye, as it is in Nature, you see I take this small wax Taper, and—shutting the Windows all close- I put it into this little brass Case, with a Convex Glass in the Side ; that the Light may go to the Earth in parallel Rays—Then I fix it in the Place of the solar Ball, and turning the Glass directly to the Earth,—you see that Hemisphere of the Earth'next the Taper enlightened, pathe other being wholly in the dark,
Euphrol. I observe it well ; and from what you shewed me on the Sphere, I eafily conceive, as the Earth revolves about its Axis, the Days and Nights must now be of equal Duration. But, pray, when do you put the Earth in Motion, to observe the Particularities of Seasons ?
Cleon. Immediately; you see it begin its Course, proceeding for the Summer Season ;--for fince, now, every Part of the Earth, equally distant from the Equator, on either Side, enjoys equal Intervals of the Sun's Presence and Absence, the Warmth or Heat of every Clime must now be at a Medium, or in a molt temperate Degree, and therefore will be productive of all the Vegetation of Plants, and pleasant Temperature of Air, that any Part of the Earth is capable of; which Qualities, I need not tell you, do every where constitute thc SPRING; which charming Season has afforded a delightful Theme to the Poets, who have variously described it. Of which I shall repeat to you some choice Specimens. The First shall be that of Virgil. See on the Shore inhabits purple Spring, Where Nightingales their Love-fick Ditties fing; See Meads with purling Streams, with Flow'rs the Graund, The Grottos cool with shady Poplars crown'd, And creeping Vines on Arbours weav'd around.
Eclogue IX, Again : When Winter's Rage abates, when chearful Hours Awake the Spring, and Spring awakes the Flow'rs; 'Tis then the Hills with pleasing Shades are crown'd, And Sleeps are sweeter on the filken Ground; With milder Beams the Sun securely fines, Fat are the Lambs, and luscious are the Wines.
But his most beautiful and grand Description of this Season is in the following Lines:
The SPRING adorns the Woods, renews the Leaves,
Then Fields the Blades of bury'd Corn disclose,
Georg. II. Among numberless Descriptions of the Moderns, Mr. Pope has the following most delicate one:
In that soft Season, when descending Show'rs
And Earth relenting, feels the genial Ray.
'Twas now the Season, when the glorious Sun
To glad the Glebe, and paint the flow'ry Fields. Mr. Thomson has made this Season the Subject of an exquisite Poem; in which, after a short Invocation or figurative Address in these Words