for. With great esteem, I have the honour to be, Reverend Sir, &c. B. FRANKLIN.

1726. TO JAMES BOWDOIN 1

1

(L. C.)

Queries and Conjectures relating to Magnetism and the Theory of the Earth Philad May 31, 1788.

DEAR SIR,

I received your Favours by Messrs. Gore, Hilliard, and Lee, with whose Conversation I was much pleased, and wished for more of it; but their stay with us was too short. Whenever you recommend any of your Friends to me, you oblige

me.

I want to know whether your Philosophical Society' receiv'd the second Volume of our Transactions. I sent it, but never heard of its arriving. If it miscarried, I will send another. Has your Society among its Books the French work Sur les Arts et les Métiers? It is voluminous, well executed, and may be useful in our country. I have bequeath'd it them in my will; but if they have it already, I will substitute something else.

Our ancient Correspondence used to have something Philosophical in it. As you are now more free from public Cares, and I expect to be so in a few Months, why may we not resume that kind of Correspondence? Our much regretted Friend Winthrop once made me the Compliment, that I was good at starting Game for Philosophers; let me try if I can start a little for you.

1 Read at a meeting of The American Philosophical Society, January 15, 1790.- ED.

2 The American Academy of Arts and Sciences. — Ed.

Has the question, how came the Earth by its Magnetism, ever been consider'd?

Is it likely that Iron Ore immediately existed when this globe was first form'd; or may it not rather be suppos'd a gradual Production of Time?

If the Earth is at present magnetical in virtue of the Masses of Iron Ore contain'd in it, might not some Ages pass before it had magnetic polarity?

Since Iron Ore may exist without that Polarity, and by being plac'd in certain Circumstances may obtain it from an external Cause, is it not possible that the Earth received its Magnetism from some such Cause?

In short, may not a magnetic Power exist throughout our System, perhaps thro' all Systems, so that if Men could make a Voyage in the Starry Regions, a Compass might be of Use? And may not such universal Magnetism, with its uniform Direction be serviceable in keeping the diurnal Revolution of a Planet more steady to the same Axis?

Lastly, as the Poles of Magnets may be changed by the Presence of stronger Magnets, might not, in ancient Times, the near Passing of some large Comet, of greater magnetic Power than this Globe of ours, have been a means of changing its Poles, and thereby wrecking and deranging its Surface, placing in different Regions the Effect of centrifugal Force, so as to raise the Waters of the Sea in some, while they were depress'd in others?

Let me add another Question or two, not relating indeed to Magnetism, but, however, to the Theory of the Earth.

Is not the finding of great Quantities of Shells and Bones of Animals (natural to hot Climates) in the cold ones of our present World, some proof that its Poles have been changed?

Is not the Supposition, that the Poles have been changed, the easiest way of accounting for the Deluge, by getting rid of the old Difficulty how to dispose of its Waters after it was over? Since, if the Poles were again to be changed, and plac'd in the present Equator, the Sea would fall there about 15 Miles in height, and rise as much in the present polar Regions; and the Effect would be proportionable, if the new Poles were plac'd anywhere between the present and the Equator.

Does not the apparent Wrack of the Surface of this Globe thrown up into long Ridges of Mountains, with Strata in various Positions, make it probable, that its internal Mass is a Fluid; but a Fluid so dense as to float the heaviest of our Substances? Do we know the Limit of Condensation Air is capable of? Supposing it to grow denser within the Surface, in the same Proportion nearly as it does without, at what Depth may it be equal in Density with Gold?

Can we easily conceive how the Strata of the Earth could have been so derang'd, if it had not been a mere shell supported by a heavier Fluid? Would not such a suppos'd internal fluid Globe be immediately sensible of a Change in the Situation of the earth's Axis, alter its Form, and thereby burst the Shell, and throw up Parts of it above the rest? As if we would alter the Position of the Fluid contain'd in the Shell of an Egg, and place its longest Diameter where the shortest now is, the Shell must break; but would be much harder to break, if the whole internal Substance were as solid and hard as the Shell.

Might not a Wave, by any means rais'd in this supposed internal Ocean of extreamly dense Fluid, raise in some degree, as it passes the present Shell of incumbent Earth,

and break it in some Places, as in Earthquakes? And may not the Progress of such Wave, and the Disorders it occasions among the Solids of the Shell, account for the rumbling Sound being first heard at a distance, augmenting as it approaches, and gradually dying away as it proceeds? A Circumstance observ'd by the Inhabitants of South America in their last great Earthquake, that Noise coming from a Place some Degrees north of Lima, and being trac'd by enquiry quite down to Buenos Ayres, proceeded regularly from North to South at the rate of Leagues per minute, as I was inform'd by a very ingenious Peruvian whom I met with at Paris.

I am ever, my very dear friend, yours most affectionately,

B. FRANKLIN.

1727. TO MATHER BYLES1

DEAR OLD FRIEND,

(L. C.)

Philada June 1, 1788.

I duly received your kind Letter of May 14, 87.2 I was then busily engag'd in attending our General Convention, which, added to the ordinary current Business of this Government, took up so much of my Time, that I was oblig'd to postpone answering many Letters of Friends which gave occasion of mislaying some of them, & among those was yours, only last Week come again to hand. I think I never receiv'd that you mention respecting the University of

1 A clergyman of Boston. For some biographical anecdotes respecting him, see Tudor's "Life of James Otis," pp. 155-160.-S.

2 In A. P. S.-ED.

Aberdeen,' but the Good will I might show on that Occasion was not of Importance enough to deserve your repeating the Acknowledgment. It was in me only paying a Debt; for I remember with Gratitude, that I owe one of my first Academical Honours to your Recommendation.

It gives me much Pleasure to understand that my Points have been of Service in the Protection of you & yours. I wish for your sake, that Electricity had really prov'd what it was at first suppos'd to be, a Cure for the Palsy. It is however happy for you, that, when Old Age and that Malady have concurr'd to infeeble you, and to disable you for Writing, you have a Daughter at hand to nurse you with filial Attention, and to be your Secretary, of which I see she is very capable, by the Elegance and Correctness of her Writing in the Letter I am now answering. I too have a Daughter, who lives with me and is the Comfort of my declining Years, while my Son is estrang'd from me by the Part he took in the late War, and keeps aloof, residing in England, whose Cause he espous'd; whereby the old Proverb is exemplified;

"My Son is my Son till he take him a Wife;

But my Daughter's my Daughter all Days of her Life."

I remember you had a little Collection of Curiosities. Please to honour with a Place in it the inclos'd Medal, which I got struck in Paris. The Thought was much approv❜d by the Connoisseurs there, and the Engraving well executed. My best Wishes attend you, being ever your affectionate Friend & humble Servant,

B. FRANKLIN.

1"It is long since I had the Pleasure of writing you by Mr. Edward Church, to thank you for your friendly mention of me in a Letter that I find was transmitted to the University of Aberdeen, I suspect whether you ever received it." Byles to Franklin, May 14, 1787. — ED.