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him to me when I was at Cambridge. He is desir ous now of entering into your service. I have ad vised him to wait upon you at New-York.
They still talk big in England, and threaten hard: but their language is somewhat civiler, at least not quite so disrespectful to us. By degrees they come to their senses, but too late, I fancy, for their interest.
We have got a large quantity of saltpetre, one hundred and twenty tori, and thirty more expected. Powder mills are now wanting : I believe we must set to work and make it by hand. But I still wish, with you, that pikes could be introduced and I would add bows and arrows: these were good weapons, and not wisely laid aside.
1. Because a man may shoot as truly with a bow as with a common musket.
2. He can discharge four arrows in the time of charging and discharging one bullet.
3. His object is not taken from his view by the smoke of his own side.
4. A flight of arrows seen coming upon them terri. fies and disturbs the enemy's attention to his business.
5. An arrow sticking in any part of a man, puts him hors du combat till it is extracted.
6. Bows and arrows are more easily provided every where than muskets and ammunition.
Polydore Virgil, speaking of one of our battles against the French in Edward the Third's reign, mentions the great confusion the enemy was thrown into sagittarum nube, from the English; and con. cludes, “ Est res profecto dictu mirabilis ut tantus ac petens exercitus a solis fere Anglicis sagittariis victus fuerit; adeo Anglus est sagittipotens, et id genus ar. morum valut." If so much execution was done by arrows when men wore some defensive armour, how much more might be done now that it is out of use !
I am glad you are come to New York, but I also wish you could be in Canada. There is a kind of suspense in men's minds here at present, waiting to see what terms will be offered from England. 1 ex. pect none that we can accept; and when that is generally seen, we shall be more unanimous and more
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 at night, and these short days have been all taken up by such a variety of business that I seldom can sit down ten minutes without interruption. God give you success, I am, with the greatest esteem,
ON THE THEORY OF THE EARTH.
TO ABBE SOULAIVE.
Passy, Sptember 22, 1782.
I RETURN the papers with some corrections. I did not find coal mines, under the calcareous rock in Derbyshire.--I 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 superficial parts of the globe seemed to me unlikely to hapa pen, if the earth were solid at the centre, I there,
fore imagined that the internal parts might be a fluid more dense, and of a greater specific gravity than any of the solids we are acqnainted with ; which there. fore might swim in or upon that fluid. Thus the surface of the globe would be a shell, capable of being broken and disordered by the violent 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 float above and upon it; and, as we know not yet the de. gree 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 ftuid occupying the internal parts of the globe might be air compresssed. 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 well as be of use in keeping alive the cen. tral 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 orinally 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 certain parts, and the mutual repulsion of other parts, to exist) all move towards their common centre: that 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, and rise till they arrive at that region of the air, which was of the same specific gra. rity with themselves, where they would rest; whiie 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 movements 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 its substance into the confusion in which we find it. I 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 all space ; 80 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 became a particular magnet. In soft or hot iron the fluid of magnetism is naturally diffused equally, when with: in 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 and grows hard in hat situation, it becomes a permanent one, the magnetic fluid not casily resuming its equilibrium. Perhaps it may be owing to the permanent magnetism of this globe, which it had not at first, that its axis is at present 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 polar and equatorial diameters. differing from each other near ten leagues, it is casy to conceive, in case some
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 wacers 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 different extremes near five leagues! Such an operation as this possibly occasioned 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. inate, which seems to have been a hot one. The globe being now become a perfect magnet, we are perhaps 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 eternal ponderous Auid; 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 explosion, but, impressing with the same force the iuid 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 see 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 will warsant.
In my present circumstances, that mode of studying the nature of the globe is out of niy power, and therefore I have permitted myself to wander a little in the wilds of fancy. With great esteem, I have the honour to be,