The mind employ'd in fearch of fecret things, To find out motion's cause and hidden springs, Through all th' etherial regions mounts on high, Views all the fpheres, and ranges all the sky; Searches the orbs, and penetrates the air With unfuccefsful toil, and fruitless care;
Till, ftopp'd by awful heights, and gulphs immense Of Wisdom, and of vaft Omnipotence,
She trembling ftands, and does in wonder gaze, Loft in the wide inextricable maze.
See, how the fun does on the middle shine, And round the globe describe th' æquator line By which wife means he can the whole furvey With a direct, or with a flanting ray, In the fucceffion of a night and day. Had the North pole been fixt beneath the fun, To Southern realms the day had been unknown: If the South pole had gain'd that nearer seat, The Northern climes had met as hard a fate. And fince the space, that lies on either fide The folar orb, is without limits wide; Grant that the fun had happen'd to prefer A feat afcant but one diameter,
Loft to the light by that unhappy place
This globe had lain a frozen, lonesome mafs. Behold the light emitted from the fun,
What more familiar, and what more unknown!
While by its spreading radiance it reveals
All nature's face, it ftill itself conceals. See how each morn it does its beams difplay, And on its golden wings bring back the day!
How foon th' effulgent emanations fly Through the blue gulph of interpofing sky! How foon their luftre all the region fills, Smiles on the vallies, and adorns the hills! Millions of miles, fo rapid is their race,
To cheer the earth, they in few moments pass.
Amazing progress! At its utmost stretch,
What human mind can this fwift motion reach ? But if, to fave fo quick a flight, you say
The ever-rolling orb's impulfive ray
On the next threads and filaments does bear Which form the fpringy texture of the air,
That those still strike the next, till to the fight The quick vibration propagates the light; 'Tis ftill as hard, if we this fcheme believe, The caufe of light's swift progrefs to conceive. With thought from prepoffeffion free, reflect On folar rays, as they the fight refpect.
The beams of light had been in vain display'd, Had not the eye been fit for vision made :
In vain the Author had the eye prepar'd
With so much skill, had not the light appear'd.
The old and new aftronomers in vain Attempt the heavenly motions to explain. First Ptolomy his fcheme celeftial wrought, And of machines a wild provifion brought : Orbs centric and eccentric he prepares, Cycles and epicycles, folid fpheres,
In order plac'd, and with bright globes inlaid, To folve the tours by heavenly bodies made.
But fo perplext, fo intricate a frame,
The latter ages with derifion name.
The comets, which at seasons downward tend, Then with their flaming equipage ascend; Venus, which in the purlieus of the fun Does now above him, now beneath him, run; The ancient ftructure of the heavens fubvert, Rear'd with vaft labour, but with little art. Copernicus, who rightly did condemn This eldest fyftem, form'd a wiser scheme; In which he leaves the fun at rest, and rolls The orb terrestrial on its proper poles; Which makes the night and day by this career, And by its flow and crooked course the The famous Dane, who oft' the modern guides, To earth and fun their provinces divides : The earth's rotation makes the night and day; The fun revolving through th' ecliptic way Effects the various feasons of the year, Which in their turn for happy ends appear.
This scheme or that, which pleases beft, embrace,
Still we the Fountain of their motion trace.
Kepler afferts these wonders may be done
By the magnetic virtue of the fun,
Which he, to gain his end, thinks fit to place
Full in the centre of that mighty space,
Which does the spheres, where planets roll, include,
And leaves him with attractive force endued.
The fun, thus feated, by mechanic laws, The earth and every distant planet draws;
By which attraction all the planets, found Within his reach, are turn'd in æther round.
If all these rolling orbs the fun obey, Who holds his empire by magnetic fway; Since all are guided with an equal force, Why are they fo unequal in their courfe? Saturn in thirty years his ring compleats, Which fwifter Jupiter in twelve repeats.
Mars three and twenty months revolving fpends; 460 The Earth in twelve her annual journey ends. Venus, thy race in twice four months is run; For his, Mercurius three demands; the Moon Her revolution finishes in one.
If all at once are mov'd, and by one spring; Why fo unequal is their annual ring?
If fome, you fay, preft with a ponderous load Of gravity, move flower in their road, Because, with weight encumber'd and opprest, These fluggish orbs th' attractive fun refist; Till you can weight and gravity explain, Those words are infignificant and vain.
If planetary orbs the Sun obey,
Why should the Moon difown his fovereign fway?
Why in a whirling eddy of her own
Around the globe terrestrial should she run? This difobedience of the Moon will prove
The Sun's bright orb does not the planet move. Philofophers may fpare their toil; in vain
They form new fchemes, and rack their thoughtful
After their various unfuccefsful ways, Their fruitless labour, and inept essays, No cause of thofe appearances they'll find, But Power exerted by th' Eternal Mind; Which through their roads the orbs celestial drives, And this or that determin'd motion gives. The Mind Supreme does all his worlds control, Which by his order this and that way roll;
From him they take à delegated force,
And by his high command maintain their course; By laws decreed ere fleeting time begun, In their fixt limits they their ftages run.
But if the Earth, and each erratic world, Around their Sun their proper centre whirl'd, Compofe but one extended vaft machine, And from one fpring their motions all begin; Does not fo wide, fo intricate a frame, Yet fo harmonious, fovereign art proclaim? Is it a proof of judgment to invent
A work of spheres involv'd, which reprefent The fituation of the orbs above,
Their fize and number fhew, and how they move? And does not in the orbs themselves appear
contrivance, and defign as clear?
This wide machine the univerfe regard, With how much kill is each apartment rear'd! The Sun, a globe of fire, a glowing mass, Hotter than melting fint, or fluid glafs, Of this our system holds the middle place.
Mercurius, nearest to the central Sun, Does in an oval orbit circling run;
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