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Dr. Stuart says, " It was observable of all | the sides showing darker than the middle. Dr. the spouts he saw, but more perceptible of the Mather's whirl was probably filled with dust, great one; that, towards the end, it began to the sides were very dark, but the vacuum appear like a hollow canal, only black in the within rendering the middle more transpaborders, but white in the middle; and though rent, he calls it a pillar of light. at first it was altogether black and opaque, yet, now, one could very distinctly perceive the sea water to fly up along the middle of this canal, as smoke up a chimney."

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And Dr. Mather, describing a whirlwind, says, a thick dark small cloud arose, with a pillar of light in it, of about eight or ten feet diameter, and passed along the ground in a tract not wider than a street, horribly tearing up trees by the roots, blowing them up in the air like feathers, and throwing up stones of great weight to a considerable height in the air, &c. "

These accounts, the one of water-spouts, the other of a whirlwind, seem, in this particular, to agree; what one gentleman describes as a tube, black in the borders, and white in the middle, the other calls a black cloud, with a pillar of light in it; the latter expression has only a little more of the marvellous, but the thing is the same; and it seems not very difficult to understand. When Dr. Stuart's spouts were full charged, that is when the whirling pipe of air was filled between a a a a and b b bb, Fig. I. with quantities of drops, and vapour torn off from the column W W Fig. II, the whole was rendered

Vac.

a

It was in this more transparent part, between b and c, that Stuart could see the spiral motion of the vapours, whose lines on the nearest and farthest side of the transparent part crossing each other, represented smoke ascending in a chimney; for the quantity being still too great in the line of sight through the sides of the tube, the motion could not be discovered there, and so they represented the solid sides of the chimney.

When the vapours reach in the pipe from the clouds near to the earth, it is no wonder now to those who understand electricity, that flashes of lightning should descend by the spout, as in that of Rome.

But you object, if water may be thus carried into the clouds, why have we not salt rains? The objection is strong and reasonable, and I know not whether I can answer it to your satisfaction. I never heard but of one salt rain, and that was where a spout passed pretty near a ship, so I suppose it to be only the drops thrown off from the spout, by the centrifugal force (as the birds were at Hatfield) when they had been carried so high as to be above, or to be too strongly centrifugal, for the pressure of the concurring winds surrounding it: and, indeed, I believe there can be no other kind of salt rain; for it has pleased the goodness of God so to order it, that the particles of air will not attract the particles of salt, though they strongly attract water.

Hence, though all metals, even gold, may be united with air, and rendered volatile, salt remains fixt in the fire, and no heat can force it up to any considerable height, or oblige the air to hold it. " Hence, when salt rises, as it will a little way, into air with water, there is instantly a separation made; the particles of water adhere to the air, and the particles of salt fall down again, as if repelled and forced off from the water by some power in the air; or, as some metals, dissolved in a proper menstruum, will quit the solvent when other matter approaches, and adhere to that, so the water quits the salt, and embraces the air; but air will not embrace the salt, and quit the water, otherwise our rains would indeed be salt, and every tree and plant on the face of the earth be destroyed, with all the animals that depend on them for subsistence-He who hath proportioned and given proper qualities to all things, was not unmindful of this. Let us adore HIM with praise and thanksgiving.

so dark, as that it could not be seen through, nor the spiral ascending motion discovered; but when the quantity ascending lessened, the pipe became more transparent, and the ascend- | ing motion visible. For by inspection of the figure given in this page, representing a section of our spout, with the vacuum in the middle, it is plain that if we look at such a hollow pipe in the direction of the arrows, and suppose opaque particles to be equally mixed in the space between the two circular lines, both the part between the arrows a and b, and that between the arrows c and d, will appear much darker than that between b and c, as there must be many more of those opaque par- By some accounts of seamen, it seems the ticles in the line of vision across the sides, column of water W W, sometimes falls sudthan across the middle. It is thus that a hair | denly; and if it be, as some say, fifteen or in a microscope evidently appears to be a pipe, twenty yards diameter, it must fall with great

force, and they may well fear for their ships. By one account, in the Transactions, of a spout that fell at Colne, in Lancashire, one would think the column is sometimes lifted off from the water, and carried over land, and there let fall in a body; but this, I suppose, happens rarely.

Stuart describes his spouts as appearing no bigger than a mast, and sometimes less; but they were seen at a league and a half dis

tance.

I think I formerly read in Dampier, or some other voyager, that a spout, in its progressive motion, went over a ship becalmed, on the coast of Guinea, and first threw her down on one side, carrying away her foremast, then suddenly whipped her up, and threw her down on the other side, carrying away her mizen-mast, and the whole was over in an instant. I suppose the first mischief was done by the fore-side of the whirl, the latter by the hinder-side, their motion being contrary.

I suppose a whirlwind, or spout, may be stationary, when the concurring winds are equal; but if unequal, the whirl acquires a progressive motion, in the direction of the strongest pressure.

When the wind that gives the progressive motion becomes stronger below than above, or above than below, the spout will be bent, and, the cause ceasing, straiten again.

Your queries, towards the end of your paper, appear judicious, and worth considering. At present I am not furnished with facts sufficient to make any pertinent answer to them; and this paper has already a sufficient tity of conjecture.

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Your manner of accommodating the accounts to your hypothesis of descending spouts is, I own, ingenious, and perhaps that hypothesis may be true. I will consider it farther, but, as yet, I am not satisfied with it, though hereafter I may be.

Here you have my method of accounting for the principal phenomena, which I submit to your candid examination.

And as I now seem to have almost written

I had often seen water-spouts at a distance, and heard many strange stories of them, but never knew any thing satisfactory of their nature or cause, until that which I saw at Antigua; which convinced me that a waterspout is a whirlwind, which becomes visible in all its dimensions by the water it carries up with it,

There appeared not far from the mouth of the harbour of St. John's, two or three water-spouts, one of which took its course up the harbour. Its progressive motion was slow and unequal, not in a strait line, but, as it were, by jerks or starts. When just by the wharf, I stood about one hundred yards from it. There appeared in the water a circle of about twenty yards diameter, which, to me, had a dreadful, though pleasing appearance. The water in this cir cle was violently agitated, being whisked、 about, and carried up into the air with great rapid and noise, and reflected a lustre, as if the in shined bright on that spot, which was more conspicuous, as there appeared a dark circle around it. When it made the shore, it carried up with the same violence shings, staves,* large picces of the roofs of houses e. and one small wooden house it lifted entir from the foundation on which it stood, carried it to the distance of fourteen feet in where it settled without breaking desetting; and, what is remarkable, though the whirlwind moved from west to d east, the house moved from east to west.Two or three negroes and a white woman, were killed by the fall of timber, which it carried up into the air and dropped again. After passing through the town, I believe it was soon dissipated; for, except tearing a large limb from a tree, and part of the cover of a sugar work near the town, I do not remember any further damage done by it. I conclude, wishing you success in your inquiry.

or

W. MERCER.

Dr. Perkins to Dr. Franklin.

a book, instead of a letter, you will think it Shooting Stars.-Read at the Royal Society,

high time I should conclude; which I beg leave to do, with assuring you that I am, &c. B. FRANKLIN.

Dr. Mercer to Dr. Franklin. Description of a Water-spout at Antigua.-Read at the Royal Society, June 24, 1756.

NEW-BRUNSWICK, November 11, 1752.

I AM favoured with your letter of the 2d instant, and shall, with pleasure, comply with your request, in describing (as well as my memory serves me) the water-spout I saw at Antigua; and shall think this, or any other service I can do, well repaid, if it contributes to your satisfaction in so curious a disquisition.

July 8, 1756.

BOSTON, May 14, 1753. I RECEIVED your letter of April last, and thank you for it. Several things in it make make me at a loss which side the truth lies on, and determine me to wait for farther evidence.

As to shooting-stars, as they are called, I know very little, and hardly know what to say. I imagine them to be passes of electric fire from place to place in the atmosphere, perhaps occasioned by accidental pressures of a non-electric circumambient fluid, and so by

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propulsion, or elicited by the circumstance of | a distant quantity minus electrified, which it shoots to supply, and becomes apparent by its contracted passage through a non-electric medium. Electric fire in our globe is always in action, sometimes ascending, descending, or passing from region to region. I suppose it avoids too dry air, and therefore we never see these shoots ascend. It always has freedom enough to pass down unobserved, but, I imagine, not always so, to pass to distant climes and meridians less stored with it.

The shoots are sometimes all one way, which, in the last case, they should be. Possibly there may be collections of particles in our atmosphere, which gradually form, by attraction, either similar ones per se, or dissimilar particles, by the intervention of others. But then, whether they shoot or explode of themselves, or by the appach of some suitable foreign collection, accimentally brought near by the usual commotions and interchanges of our atmosphere, especially when the higher and lower regions intermix, before change of winds and weather, leave. I believe I have now said enough of what I know nothing about. If it should serve for your amusement, or any way oblge you, all I aim at, and shall, at your desir, be always ready to say what I think, as am sure of your candour. m th

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Dr. Perkins to Dr. Franklin.
Water-spouts and Whirlwinds.-Rea at the
Royal Society, July 8, 1756.

SPOUTS have been generally believed ascents of water from below, to the region of the clouds, and whirlwinds, the means of conveyance. The world has been very well satisfied with these opinions, and prejudiced with respect to any observations about them. Men of learning and capacity have had many opportunities in passing those regions where these phenomena were most frequent, but seem industriously to have declined any notice of them, unless to escape danger, as a matter of mere impertinence in a case so clear and certain as their nature and manner of operation are taken to be. Hence it is has been very difficult to get any tolerable accounts of them. None but those they fell near can inform us any thing to be depended on; three or four such instances follow, where the vessels were so near, that their crews could not avoid knowing something remarkable with respect to the matters in question.

Captain John Wakefield, junior, passing the Straits of Gibraltar, had one fall by the side of his ship; it came down of a sudden, as they think, and all agree the desct was certain.

Captain Langstaff, on a voyage to the West

Indies, had one come across the stern of his vessel, and passed away from him. The water came down in such quantity that the present capt. Melling, who was then a common sailor at the helm, says it almost drowned him, running into his mouth, nose, ears, &c. and adds, that it tasted perfectly fresh.

One passed by the side of captain Howland's ship, so near that it appeared pretty plain that the water descended from first to last.

Mr. Robert Spring was so near one in the Straits of Malacca, that he could perceive it to be a small very thick rain.

All these assure me, that there was no wind drawing towards them, nor have I found any others that have observed such a wind.

It seems plain, by these few instances, that whirlwinds do not always attend spouts; and that the water really descends in some of them. But the following consideration, in confirmation of this opinion, may, perhaps, render it probable that all the spouts are descents.

It seems unlikely that there should be two sorts of spouts, one ascending and the other descending.

It has not yet been proved that any one spout ever ascended. A specious appearance is all that can be produced in favour of this; and those who have been most positive about it, were at more than a league's distance when they observed, as Stuart and others, if I am not mistaken. However, I believe it impossible to be certain whether water ascends or descend at half the distance.

It may not be amiss to consider the places where they happen most. These are such as are liable to calms from departing winds on both sides, as on the borders of the equinoctial trade winds, calms on the coast of Guinea, in the Straits of Malacca, &c. places where the under region of the atmosphere is drawn off horizontally. I think they do not come where the calms are without departing winds; and I take the reason to be, that such_place and places where winds blow towards one another, are liable to whirlwinds, or other ascents of the lower region, which I suppose contrary to spouts. But the former are liable to descents, which I take to be necessary to their production. Agreeable to this, it seems reasonable to believe, that any Mediterranean sea should be more subject to spouts than others. The sea usually so called is so. The Straits of Malacca is. Some large gulphs may probably be so, in suitable latitudes; so the Red Sea, &c. and all for this reason, that the heated lands on each side draw off the under region of the air, and make the upper descend, whence sudden and wonderful condensations may take place, and make these descents.

It seems to me, that the manner of their ap

pearance and procedure, favour the notion of a descent.

More or less of a cloud, as I am imformed, always appears over the place first; then a spattering on the surface of the water below; and when this is advanced to a considerable degree, the spout emerges from the cloud, and descends, and that, if the causes are sufficient, down to the places of spattering, with a roaring in proportion to the quantity of the discharge; then it abates, or stops, sometimes more gradually, sometimes more suddenly.

I must observe a few things on these particulars, to show how I think they agree with my hypothesis.

The preceding cloud over the place shows condensation, and, consequently, tendency downwards, which therefore must naturally prevent any ascent. Besides that, so far as I can learn, a whirlwind never comes under a cloud, but in a clear sky.

The spattering may be easily conceived to be caused by a stream of drops, falling with great force on the place, imagining the spout to begin so, when a sudden and great condensation happens in a contracted space, as the Ox-Eye on the coast of Guinea.

The spout appearing to descend from the cloud seems to be, by the stream of nearly contiguous drops bringing the air into consent, so as to carry down a quantity of the vapour of the cloud; and the pointed appearance it makes may be from the descending course being swiftest in the middle, or centre of the spout: this naturally drawing the outer parts inward, and the centre to a point; and that will appear foremost that moves swiftest. The phenomenon of retiring and advancing, I think may be accounted for, by supposing the progressive motion to exceed or not equal the consumption of the vapour by condensation. Or more plainly thus: the descending vapour which forms the apparent spout, if it be slow in its progress downwards, is condensed as fast as it advances, and so appears at a stand; when it is condensed faster than it advances, it appears to retire; and vice versa.

Its duration, and manner of ending, are as the causes, and may vary by several accidents. The cloud itself may be so circumstanced as to stop it; as when, extending wide, it weighs down at a distance round about, while a small circle at the spout being exonerated by the discharge, ascends and shuts up the passage. A new determination of wind may, perhaps, stop it too. Places liable to these appearances are very liable to frequent and sudden alterations of it.

Such accidents as a clap of thunder, firing cannon, &c. may stop them, and the reason may be, that any shock of this kind may occasion the particles that are near cohering, immediately to do so; and then the whole, thus condensed falls at once (which is what I

suppose is vulgarly called the breaking of the spout) and in the interval, between this pe riod and that of the next set of particles being ready to unite, the spout shuts up. So that if this reasoning is just, these phenomena agree with my hypothesis.

The usual temper of the air, at the time of their appearance, if I have a right information, is for me too; it being then pretty cool for the season and climate; and this is worth remark, because cool air is weighty, and will not ascend; besides, when the air grows cool, it shows that the upper region descends, and conveys this temper down; and when the tempers are equal, no whirlwind can take place. But spouts have been known, when the lower region has been really cold. Gordon's spout in the Downs is an instance of this-(vide Philosophical Transactions)where the upper region was probably not at all cooler, if so cold as the lower: it was a cold day in the month of March, hail followed, but not snow, and it is observable, that not so much as hail follows or accompanies them in moderate seasons or climes, when and where they are most frequent. However, it is not improbable, that just about the place of descent may be cooler than the neighbouring parts, and so favour the wonderful celerity of condensation. But, after all, should we allow the under region to be ever so much the hottest, and a whirlwind to take place in it: suppose then the sea-water to ascend, it would certainly cool the spout, and then, query, whether it would not very much, if not wholly, obstruct its progress.

It commonly rains when spouts disappear, if it did not before, which it frequently does not, by the best accounts I have had; but the cloud increases much faster after they disappear, and it soon rains. The first shows the spout to be a contracted rain, instead of the diffused one that follows; and the latter that the cloud was not formed by ascending water, for then it would have ceased growing when the spout vanished.

However, it seems that spouts have sometimes appeared after it began to rain; but this is one way a proof of my hypothesis, viz. as whirlwinds do not come under a cloud.

I forgot to mention, that the increase of cloud, while the spout subsists, is no argument of an ascent of water, by the spout. Since thunder-clouds sometimes increase greatly while it rains very hard.

Divers effects of spouts seem not so well accounted for any other way as by descent.

The bush round the feet of them seems to be a great spray of water made by the violence of descent, like that in great falls of water from high precipices.

The great roar, like some vast inland falls, is so different from the roar of whirlwinds, by all accounts, as to be no ways compatible.

The throwing things from it with great force, instead of carrying them up into the air, is another difference.

There seems some probabilty that the sailors' traditionary belief, that spouts may break in their decks, and so destroy vessels, might originate from some facts of that sort in former times. This danger is apparent on my hypothesis, but it seems not so on the other: and my reason for it is, that the whole column of a spout from the sea to the clouds cannot, in a natural way, even upon the largest supposition, support more than about three feet water, and from truly supposable causes, not above one foot, as may appear more plainly by and bye. Supposing now the largest of these quantities to rise, it must be disseminated into drops, from the surface of the sea to the region of the clouds, or higher; for this reason it is quite unlikely to be collected into masses, or a body, upon its falling; but would descend in progression according to the several degrees of altitude the different portions had arrived at when it received this new determination.

Now that there cannot more rise upon the common hypothesis than I have mentioned, may appear probable, if we attend to the only efficient cause in supposed ascending spouts, viz. whirlwinds.

We know, that the rarefaction of the lower, and the condensation of the upper region of air, are the only natural causes of whirlwinds. Let us then suppose the former as hot as their greatest summer heat in England, and the latter as cold as the extent of their winter. These extremes have been found there to alter the weight of the air one tenth, which is equal to a little more than three feet water. Were this case possible, and a whirlwind take place in it, it might act with a force equal to the mentioned difference. But as this is the whole strength, so much water could not rise; therefore to allow it due motion upwards, we must abate, at least, one fourth part, perhaps more, to give it such a swift ascension as some think usual. But here several difficulties occur, at least they are so to me. As, whether this quantity would render the spout opaque? since it is plain that in drops it could not do so. How, or by what means it may be reduced small enough? or, if the water be not reduced into vapour, what will suspend it in the region of the clouds when exonerated there; and, if vapourized while ascending, how can it be dangerous by what they call the breaking? For it is difficult to conceive how a condensatize power should instantaneously take place of a rarefying and disseminating

one.

The sudden fall of the spout, or rather, the sudden ceasing of it, I accounted for, in my way, before. But it seems necessary to mention something I then forgot. Should it

be said to do so (i. e.) to fall, because all the lower rarefied air is ascended, whence the whirlwind must cease, and its burden drop; I cannot agree to this, unless the air be observed on a sudden to have grown much colder, which I cannot learn has been the case. Or should it be supposed that the spout was, on a sudden, obstructed at the top, and this the cause of the fall, however plausible this might appear, yet no more water would fall than what was at the same time contained in the column, which is often, by many and satisfactory accounts to me, again far from being the case.

We are,

I think, sufficiently assured, that not only tons, but scores or hundreds of tons descend in one spout. Scores of tons more than can be contained in the trunk of it, should we suppose water to ascend.

But, after all, it does not appear that the above-mentioned different degrees of heat and cold concur in any region where spouts usually happen, nor, indeed, in any other.

Observations on the Meteorological Paper; by a Gentleman in Connecticut.-Read at the Royal Society, Nov. 4, 1756.

"AIR and water mutually attract each other, (saith Mr. F.) hence water will dissolve in air, as salt in water." I think that he hath demonstrated, that the supporting of salt in water is not owing to its superfices being increased, because "the specific gravity of salt is not altered by dividing of it, any more than that of lead, sixteen bullets of which, of an ounce each, weigh as much in water as one of a pound." But yet, when this came to be applied to the supporting of water in air, I found an objection rising in my mind.

In the first place, I have always been loth to seek for any new hypothesis, or particular law of nature, to account for any thing that may be accounted for from the known general, and universal law of nature; it being an argument of the infinite wisdom of the Author of the world, to effect so many things by one general law. Now I had thought that the rising and support of water, in air, might be accounted for from the general law of gravitation, by only supposing the spaces occupied by the same quantity of water increased.

And, with respect to the lead, I queried thus in my own mind: whether if the superfices of a bullet of lead should be increased four or five fold by an internal vacuity, it would weigh the same in water as before. I mean, if a pound of lead should be formed into a hollow globe, empty within, whose superfices should be four or five times as big as that of the same lead when a solid lump, it would weigh as much in water as before. I supposed it would not. If this concavity was filled with water, perhaps it might; if

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