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decisive: then your proposed solemn league and covenant will go better down, and perhaps most of our other strong measures be adopted.

I am always glad to hear from you, but I do not deserve your favours, being so bad a correspondent. My eyes will now hardly serve me to write by night, and these short lays have been all taken up by such variety of business that I seldum can sit down ten ninutes without interruption, God give you success I ain, with the greatest esteem,

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1 RETURN the papers with some corrections. I did not find coal mines, under the calcareous rock in Derbyshire.-1 only remarked, that at the lowest part of that rocky mountain, which was in sight, there were oyster shells mixed with the stone; and part of the high country of Derby being probably as much above the level of the sea, as the coal mines of Whitehaven were below, it seemed a proof that there had been a great bouleversement in the surface of that island, some part of it having been depressed under the sea, and other parts, which had been under it, being raised above it. Such changes in the super ficial parts of the globe seemed to me unlikely to hap pen, if the earth were solid at the centre. 1 thera

fre imagined that the internal parts might be a fluid more dense, and of greater specific gravity than any (f the solids we are acquainted with; which therefore might swim in or upon that fluid. Thus the sur face of the globe would be a shell, capable of being roken and disordered by the viclent movements of fluid on which it rested. And, as air has been compressed by art so as to be twice as dense as water, in which case, if such air and water could be contained in a strong glass vessel, the air would be seen to take the lowest place, and the water to oa above and upon it; and, as we know not yet the degree of density to which air may be compressed, and M. Amontons calculated, that, its density increasing as it approached the centre in the same proportion as above the surface, it would at the depth of leagues, be heavier than gold, possibly the dense fluid occupying the internal parts of the globe might be air compressed. And as the force of expansion in dense air when heated, is in proportion to its density; this central air might afford another agent to move the surface, as weil as be of use in keeping alive the central fires; though, as you observe, the sudden rare. faction of water, coming into contact with those fires, may be an agent sufficiently strong for that purpose, when acting between the incumbent and the fluid on which it rests.

If one might indulge imagination in supposing how such a globe was formed, I should conceive, that all the elements in separate particles, being originally mixed in confusion, and occupying a great space, they would as soon (as soon as the Almighty fiat ordained gravity, or the mutual attraction of cer ain parts, and the mutual repulsion of other parts, to xist) all move towards their common centre: tha the air being a fluid whose parts repel each other though drawn to the common centre by their gravity, would be densest towards the centre, and rarer as more remote; consequently, all bodies, lighter than the central parts of that air, and immersed in it, would recede from the centre, an 1 rise till they arrive at that region of the air, which was of the saine specific gravity with themselves, where they would rest; while

other matter mixed with the lighter air, would descend, and the two, meeting, would form the shell of the first earth, leaving the upper atmosphere nearly clear. The original movement of the parts towards their common centre would form a whirl there; which would continue in the turning of the new-formed globe upon its axis, and the greatest diameter of the shell would be in its equator. If by any accident afterwards the axis should be changed, the dense internal fluid, by altering its form, must burst the shell, and throw all substance into the confusion in which w find it. will not trouble you at present with my fancies concerning the manner of forming the rest of our system. Superior beings smile on our theories, and at our presumption in making them. I will just mention that your observation of the ferruginous nature of the lava, which is thrown out from the depths of our volcanoes, gave me great pleasure. It has long been a supposition of mine, that the iron contained in the substance of the globe has made it capable of becoming, as it is, a great magnet; that the fluid of magnetism exists perhaps in al! space; so that there is a magnetical North and South of the universe, as well as of this globe; and that if it were possible for a man to fly from star to star, he might govern his course by the compass; that it was by the power of this general magnetism this globe beame a particular magnet. In soft or hot iron the fluid of magnetism is naturally diffused equally; when within the influence of a magnet, it is drawn to one end of the iron, made denser there and rarer at the other. While the iron continues soft and hot, it is only a temporary magnet: if it cools or grows hard in tha situation, it becomes a permanent one, the inagnetio fluid not easily resuming its equilibrium. Perhap it may be owing to the permanent magnetism of this globe, which it had not at first, that its axis is at pre sent kept parallel to itself, and not liable to the changes it formerly suffered, which occasioned the rupture of its shell, the submersions and emersions of its lands and the confusion of its seasons. The present pola and equatorial diameters differing from each othes near ten leagues, it is easy to conceive, in case soms

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power should shift the axis gradually, and place it in
the present equator, and make the new equator pass
through the present poles, what a sinking of the wa-
ters would happen in the present equatorial regions,
and what a rising in the present polar regions; so that
vast tracts would be discovered that now are under
water, and others covered that now are dry, the water
rising and sinking in the differet extremes near five
leagues! Such an operation as this possibly occasion
ed much of Europe, and, among the rest, of this
mountain of Passy, on which I live, and which is
composed of limestone, rock and sea shells, to be
abandoned by the sea, and to change its ancient cli-
mate, which seems to have been a hot one. The globe
being now become a perfect magnet, we are perlaps
safe from any future change of its axis. But we are
still subject to the accidents on the surface, which
are occasioned by a wave in the internal ponderous
fluid and such a wave is produced by the sudden
violent explosion you mention, happening from the
junction of water and fire under the earth, which not
only lifts the incumbent earth that is over the explo-
sion, but, inpressing with the same force the fluid
under it, creates a wave that may run a thousand
leagues, lifting, and thereby shaking successively, all
the countries under which it passes. I know not
whether I have expressed myself so clearly, as not
to get out of your sight in these reveries. If they
occasion any new inquiries, and produce a better
hypothesis, they will not be quite useless. You set
I have given a loose to imagination, but I approve
much more your method of philosophising, which
proceeds upon actual observation, makes a collection
of facts, and concludes no farther than those facts wil
In my present circumstances, that mod
of studying the nature of the globe is out of my power
and therefore I have permitted myself to wander a
little in the wilds of fancy. With great esteem,
have the nonour to be,

warrant.

1

Sir, &c.

B. FRANKLIN

P. S. I have heard that chemists can by their art decompose stone and wood, extracting a considerable quantity of water from the one, and air from the other. It seems natural to conclude from this, that water and air were ingredients in their originel composition: for men cannot make new matter of any kind. In the same manner do we not suppose, that when we consume combustibles of all kinds, and produce heat or light, we do not create the hea or light, we only decompose a subs.ance which re ceived it originally as a part of its composition. Heat may thus be considered as originally in a fluid state; but, attracted by organized bodies in their growth, becomes a part of the solid. Besides this,

can conceive that, in the first assemblage of the particles of this earth is composed, each brought its portion of the loose heat that had been connected with i and the whole, when pressed together, produeed ine internal fire which still subsists.

LOOSE THOUGHTS ON THE UNIVER-
SAL FLUID, &c.

Passy, June 25, 1784.

UNIVERSAL space, as far as we know of it, seems t be filled with a subtle fluid, whose motion, or vibra ion, is called light.

This fluid may possibly be the same with that which, being attracted by and entering into other more solid matter, dilates the substance, by separating the constituent particles, and so rendering some solids fluid, and maintaining the fluidity of

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