Give them the fituation they defire;
But let us then, ye fages, next enquire,
What cause of their cohesion can you find?
What props fupport, what chains the fabrick bind ?
Why do not beafts that move, or stones that lie
Loofe on the field, through distant regions fly?
Or why do fragments, from a mountain rent,
Tend to the earth with fuch a swift defcent?
Those who afcribe this one determin'd course
Of ponderous things to gravitating force,
Refer us to a quality occult,
To fenfelefs words, for which while they infult
With juft contempt the famous Stagyrite,
Their fchools fhould blefs the world with clearer light.
Some, the round earth's cohefion to fecure,
For that hard tafk employ magnetic power.
Remark, fay they, the globe; with wonder own
Its nature, like the fam'd attractive stone.
This has its axis, fo th' observer tells,
Meridians, poles, æquator, parallels.
To the terreftrial poles by conftant fate
Th' obfequious poles themselves accommodate,
And, when of this pofition difpoffest,
They move, and frive, nor ever will they reft,
Till their lov'd fituation they regain,
Where pleas'd they fettle, and unmov'd remain.
And should you, fo experience does decide,
Into fmall parts the wondrous ftone divide,
Ten thousand of minuteft fize exprefs
The fame propenfion, which the large poffefs.
Hence all the globe ('tis faid) we may conclude
With this prevailing energy endued :
That this attractive, this furprizing stone
Has no peculiar virtue of its own;
Nothing but what is common to the whole,
To fides, to axis, and to either pole.
The mighty magnet from the centre darts
This ftrong, though fubtle force, through all the parts; Its active rays, ejaculated thence,
Irradiate all the wide circumference..
And of its due attractive power poffeft;
While adverse ways the adverse atoms draw
With the fame ftrength, by nature's conftant law
Balanc'd and fixt; they can no longer move;
Through gulphs immenfe no more unguided rove.
If cords are pull'd two adverse ways, we find
The more we draw them, they the faster bind.
So when with equal vigour Nature strains
This way and that these fine mechanic chains,
They fix the earth, they part to part unite,
Preferve their structure, and prevent their flight.
Preffure, they fay, and weight, we must disown,
As things occult, by no ideas known,
And on the earth's magnetic power depend
To fix its feat, its union to defend.
Let us this fam'd hypothefis furvey,
And with attentive thought remark the way,
How earth's attractive parts their force display.
The mafs, 'tis faid, from its wide bofom pours
Torrents of atoms, and eternal showers
Of fine magnetic darts, of matter made
So fubtle, marble they with ease pervade :
Refin'd, and (next to incorporeal) thin,
Not by Aufonian glaffes to be feen.
Thefe emanations take their conftant flight
Swift from the earth, as from the fun the light;
To a determin'd diftance they afcend,
And there inflect their courfe, and downward tend.
What can infult unequal Reafon more,
Than this magnetic, this myfterious power?
That cords and chains, beyond conception fmall,
Should gird and bind so fast this mighty ball!
That active rays fhould fpring from every part,
And, though fo fubtle, fhould fuch force exert!
That the light legions should be sent abroad,
Range all the air, and traverfe every road!
To ftated limits fhould excurfions make,
Then backward of themfelves their journey take;
Should in their way to folid bodies cling,
And home to earth the captive matter bring;
Where all things on its surface spread are bound
By their coercive vigour to the ground!
Can this be done without a Guide Divine?
Should we to this hypothefis incline?
Say, does not here confpicuous Wisdom shine?
Who can enough magnetic force admire?
Does it not counsel and defign require
To give the earth this wondrous energy,
In fuch a measure, such a juft degree,
That it should ftill perform its deftin'd task,
As nature's ends and various uses ask?
For, fhould our globe have had a greater share 220
Of this ftrong force, by which the parts cohere,
Things had been bound by fuch a powerful chain,
That all would fix'd and motionless remain ;
All men, like ftatues, on the earth would ftand,
Nor would they move the foot, or ftretch the hand;
Birds would not range the fkies, nor beafts the woods,
Nor could the fith divide the ftiffen'd floods.
Again, had this ftrange energy been lefs,
Defect had been as fatal as excefs.
For want of cement ftrong enough to bind
The ftructure faft, huge ribs of rock, disjoin'd
Without an earthquake, from their base would start,
And hills unhing'd from their deep roots depart.
And, while our orb perform'd its daily race,
All beings, found upon its ample face,
Would, by that motion diffipated, fly
Whirl'd from the globe, and scatter through the sky: They muft, obedient to mechanic laws,
Affemble where the ftronger magnet draws;
Whether the Sun that ftronger magnet proves,
Or else fome planet's orb that nearer moves.
Who can unfold the caufe that does recall
Magnetic rays, and make them backward fall?
If these effluvia, which do upward tend,
Because less heavy than the air, afcend;
Why do they ever from their height retreat,
And why return to feek their central feat?
From the fame cause, ye fons of art, declare
Can they by turns defcend, and rife in air?
Prodigious 'tis, that one attractive ray
Should this way bend, the next an adverse way;
For, fhould th' unfeen magnetic jets defcend
All the fame way, they could not gain their end;
They could not draw and bind the fabrick fait,
Unless alike they every part embrac'd.
How does Cartefius all his finews ftrain,
How much he labours, and how much in vain,
The earth's attractive vigour to explain !
This bold contriver thus his thoughts conveys:
Inceffant ftreams of thin inagnetic rays
Gufh from their fountains, with impetuous force,
In either pole, then take an adverfe course :
Thofe from the Southern pole the Northern feek;
The Southern thofe that from the Northern break:
In either pole thefe rays emitted meet
Small pores provided, for their figures fit;
Still to and fro they circulating país,
Hold all the frame, and firmly bind the mass.
Thus he the parts of earth from flight reftrains,
And girds it faft by fine imagin'd chains.
But oh! how dark is human reafon found!
How vain the man, with wit and learning crown'd!
How feeble all his ftrength, when he etlays
To trace dark Nature, and detect her ways;
Unless he calls its Author to his aid,
Who every fecret fpring of motion laid,
Who over all his wondrous works pretides,
And to their useful ends their caufes guides!
These paths in vain are by enquirers trod;
There's no philofophy without a God.
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