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which I viewed with a good deal of attention ; tion, is very observable in the cloud from and though it be now forty years since I saw whence the spout issues. No salt-water, I it, it made so strong an impression on me, that am persuaded, was ever observed to fall from I very distinctly remember it. These water- the clouds, which must certainly have hapspouts were in the calm latitudes, that is, be- pened if sea-water had been raised by a spout. tween the trade and the variable winds, in the month of July. That spout which passed so near us was an inverted cone, with the tip or |
Answer to the foregoing Observations, by b. apex towards the sea, and reached within
Franklin.-Read at the Royal Society, Nov. about eight feet of the surface of the sea, its
4, 1756. basis in a large black cloud. We were en- I AGREE with you, that it seems absurd to tirely becalmed. It passed slowly by the suppose that a body can act where it is nol. vessel. I could plainly observe, thaťa violent I have no idea of bodies at a distance attractstream of wind issued from the spout, which ing or repelling one another without the asmade a hollow of about six feet diameter in sistance of some medium, though I know not the surface of the water, and raised the water what that medium is, or how it operates. in a circular uneven ring round the hollow, When I speak of attraction or repulsion, I in the same inanner that a strong blast from make use of those words for want of others a pair of bellows would do when the pipe is more proper, and intend only to express efplaced perpendicular to the surface of the fects which I see, and not causes of which I water; and we plainly heard the same hissing am ignorant. When I press a blown bladder noise which such a blast of wind must produce between my knees, and find I cannot bring on the water. I am very sure there was no- its sides together, but my knees feel a springy thing like the sucking of water from the sea matter, pushing them back to a greater disinto the spout, unless the spray, which was tance, or repelling them, I conclude that the raised in a ring to a small height, could be air it contains is the cause. And when I mistaken for a raising of water. I could operate on the air, and find I cannot by presplainly distinguish a distance of about eight sure force its particles into contact, but they feet between the sea and the tip of the cone, still spring back against the pressure, I conin which nothing interrupted the sight, which ceive there must be some medium between must have been, had the water been raised its particles that prevents their closing, though from the sea.
I cannot tell what it is. And if I were acIn the same voyage I saw several other quainted with that medium, and found its parspouts at a greater distance, but none of them ticles to approach and recede from each other, whose tip of the cone came so near the surface according to the pressure they suffered, I of the water. In some of them the axis of should imagine there must be some finer methe cone was considerably inclined from the dium between them, by which these operaperpendicular, but in none of them was there tions were performed. the least appearance of sucking up of water. I allow that increase of the surface of a Others of them were bent or arched. I be- body may occasion it to descend slower in air, lieve that a stream of wind issued from all of water, or any other fluid: but do not conceive, them, and it is from this stream of wind that therefore, that it lessens its weight. Where vessels are often overset, or founder at sea the increased surface is so disposed as that in suddenly. I have heard of vessels being over- its falling a greater quantity of the fluid it set when it was perfectly calm, the instant sinks in must be moved out of its way, a before the stream of wind struck them, and greater time is required for such removal. immediately after they were overset; which Four square feet of sheet lead sinking in water could not otherwise be but by such a stream broadways, cannot descend near so fast as it of wind from a cloud.
would edgeways, yet its weight in the hydroThat wind is generated in clouds will not static balance would, I imagine, be the same, admit of a dispute. Now if such wind be ge- whether suspended by the middle or by the nerated within the body of the cloud, and corner. issue in one particular place, while it finds no I make no doubt but that ridges of high passage in the other parts of the cloud, I think mountains do often interrupt, stop, reverberit may not be difficult to account for all the ate, or turn the winds that blow against them, appearances in water-spouts : and from hence according to the different degrees of strength the reason of breaking those spouts, by firing of the winds, and angles of incidence. I supa cannon-ball through them, as thereby a ho- pose too, that the cold upper parts of mounrizontal vent is given to the wind. When tains may condense the warmer air that comes the wind is spent, which dilated the cloud, or near them, and so by making it specifically the fermentation ceases, which generates the heavier, cause it to descend on one or both air and wind, the clouds may descend in a sides of the ridge into the warmer valleys, prodigious fall of water or rain. A remarka- which will seem a wind blowing from the ble intestine motion, like a violent fermenta- / mountains.
Vol. II. ... 2 X
Damp winds, though not colder by the ther- times appearing with a small bending, or elmometer, give a more easy sensation of cold bow, in the middle. I never saw any hang than dry ones, because (to speak like an elec- perpendicularly down. It is small at the trician) they conduct better; that is, are het- lower end, seeming no bigger than one's arm, ter fitted to convey away the heat from our but still fuller towards the cloud from whence bodies. The body cannot feel without itself; it proceeds. our sensation of cold is not in the air without When the surface of the sea begins to the body, but in those parts of the body which work, you shall see the water for about one have been deprived of their heat by the air. hundred paces in circumference foam and My desk, and its lock, are, I suppose, of the move gently round, till the whirling motion same temperament when they have been long increases; and then it flies upwards in a exposed to the same air; but now if I lay my pillar, about one hundred paces in compass at hand on the wood, it does not seem as cold to the bottom, but gradually lessening upwards, me as the lock; because (as I imagine) wood to the smallness of the spout itself, through is not so good a conductor, to receive and con- which the rising sea-water seems to be convey away the heat from my skin, and the ad- veyed into the clouds. This vissibly appears jacent flesh, as metal is. Take a piece of. by the clouds increasing in bulk and blackwood, of the size and shape of a dollar, be- ness. Then you shall presently see the tween the thumb and finger of one hand, and cloud drive along, though before it seemed a dollar, in like manner, with the other hand : to be without any motion. The spout also place the edges of both, at the same time, in keeping the same course with the cloud, and the flame of a candle: and though the edge of still sucking up the water as it goes along, the wooden piece takes flame, and the meta) and they make a wind as they go. Thus it piece does not, yet you will be obliged to drop continues for half an hour, more or less, until the latter before the former, it conducting the the sucking is spent, and then breaking off, heat more suddenly to your fingers. Thus all the water which was below the spout, or we can, without pain, handle glass and china pendulous piece of cloud, falls down again cups filled with hot liquors, as tea, &c. but into the sea, making a great noise with its not silver ones. A silver tea-pot must have falling and clashing motion in the sea. a wooden handle. Perhaps it is for the same It is very dangerous for a ship to be under reason that woollen garments keeping the body a spout when it breaks; therefore we always warmer than linen ones equally thick; woollen endeavour to shun it, by keeping at a diskeeping the natural heat in, or, in other words, tance, if possibly we can. But for want of not conducting it out to air.
wind to carry us away, we are often in great In regard to water-spouts, having, in a long fear and danger, for it is usually calm when letter to a gentleman of the same sentiment spouts are at work, except only just where with you as to their direction, said all that I they are. Therefore men at sea, when they have to say in support of my opinion; I need see a spout coming, and know not how to not repeat the arguments therein contained, avoid it, do sometimes fire shot out of their as I intend to send you a copy of it by some great guns into it, to give it air or vent, that other opportunity, for your perusal. I ima- so it may break; but I did never hear that gine you will find all the appearances you it proved to be of any benefit. saw, accounted for by my hypothesis. I thank And now we are on this subject, I think it you for communicating the account of them. not amiss to give you an account of an acAt present I would only say, that the opinion cident that happened to a ship once on the of winds being generated in clouds by fer-coast of Guinea, some time in or about the mentation, is new to me, and I am unac- 1 year 1674. One capt. Records of London, quainted with the facts on which it is founded. bound for the coast of Guinea, in a ship of I likewise find it difficult to conceive of winds three hundred tons, and sixteen guns, called confined in the body of clouds, which I ima- the Blessing, when he came into latitude gine have little more solidity than the fogs on seven or eight degrees north, he saw several the earth's surface. The objection from the spouts, one of which came directly towards the freshness of rain-water is a strong one, but I ship, and he having no wind to get out of the think I have answered it in the letter above way of the spout, made ready to receive it by mentioned, to which I must beg leave, at pre-furling the sails. It came on very swift, and sent, to refer you.
| broke a little before it reached the ship, making a great noise, and raising the sea
round it, as if a great house, or some such Extracts from Dampier's Voyages.-Read
d thing, had been cast into the sea. The fury at the Royal Society, December 16, 1756. Iof the wind still lasted, and took the ship on
A SPOUT is a small ragged piece, or part of a the starboard-bow with such violence, that it cloud, hanging down about a yard seemingly, snapt off the boltsprit and foremast both at from the blackest part thereof. Commonly it once, and blew the ship all along, ready to hangs down sloping from thence, or some-'overset it; but the ship did presently right again, and the wind whirling round, took the ceived much wind in it as it passed by.”_Vol. ship a second time with the like fury as be- iii. page 223. fore, but on the contrary side, and was again . like to overset her the other way: the mizen- / Account of another Spout--from the same. mast felt the fury of this second blast, and was snapt short off, as the foremast and boltsprit!
1 “ We saw a spout but a small distance from had been before. The mainmast and main
m us; it fell down out of a black cloud that top-mast received no damage for the fury of yielded great store of rain, thunder, and lightthe wind (which was presently over) did not
pt ning. This cloud hovered to the southward reach them. Three men were in the foretop
m of us for the space of three hours, and then when the foremast broke, and one on the bolt
drew to the westward a great pace, at which sprit, and fell with them into the sea, but all
time it was that we saw the spout, which of them were saved. I had this relation from
hung fast to the cloud till it broke, and then Mr. John Canby, who was then quarter-master
the cloud whirled about to the south-east, and steward of her; one Abraham Wise was
then to the north-east, where meeting with chief-mate, and Leonard Jefferies second
an island, it spent itself, and so dispersed; mate.
and immediately we had a little of the tail of it, We are usually much afraid of them, yet
having had none before.”—Vol. iii. page 182. this was the only damage that I ever heard done by them. They seem terrible enough, C. Colden to Dr. Franklin.-Read at the the rather because they come upon you while | Royal Society, December 6, 1756. you lie becalmed, like a log in the sea, and
April 2, 1754. cannot get out of their way. But though I Any knowledge I have of the winds, and have seen and been beset by them often, yet other changes which happen in the atmothe fright was always the greatest of the sphere, is so very detective, that it does not harm. -Dampier, vol. i. page 451.
deserve the name; neither have I received any satisfaction from the attempts of others
on this subject. It deserves then your Account of a Spout on the coast of New
thoughts, as a subject in which you may disGuinea--from the same.
tinguish yourself, and be usetul. • We had fair clear weather, and a fine Your notion of some things conducting heat moderate gale from south-east to east by north; or cold better than others, pleases me, and I but at day-break the clouds began to Ay, and wish you may pursue the scent. If I rememit lightened very much in the east north-east. | ber right, Dr. Boerhaave, in his chemistry, At sun rising the sky looked very red in the thinks that heat is propagated by the vibration east near the horizon; and there were many of a subtle elastic fluid, dispersed through the black clouds both to the south and north of it. atmosphere and through all bodies. Sir Isaac About a quarter of an hour after the sun was Newton says, there are many phenomena to up, there was a squall to the wind ward of us, prove the existence of such a fluid: and this when, on a sudden, one of our men on the fore- opinion has my assent to it. I shall only castle, called out that he saw something observe that it is essentially different from astern, but could not tell what. I looked out that which I call ether; for ether, properly for it, and immediately saw a spout beginning speaking, is neither a fluid nor elastic; its to work within a quarter of a mile of us, ex- power consists in re-acting any action comactly in the wind; we presently put right be-municated to it, with the same force it refore it. It came very swiftly, whirling the ceives the action. water up in a pillar, about six or seven yards I long to see your explication of waterhigh. As yet I could not see any pendulous spouts, but I must tell you before hand, that it cloud from whence it might come, and was will not be easy for you to convince me that in hopes it would soon lose its force. In four the principal phenomena were not occasioned or five minutes time it came within a cable's, by a stream of wind issuing with great force. length of us, and passed away to leeward ; / my eyes and ears both concurring to give me and then I saw a long pale stream coming this sentiment, I could have no more evi. down to the whirling water. This stream
dence than to feel the effects, which I had no was about the bigness of a rainbow. The up inclination to do.' per end seemed vastly high, not descending
It surprises me a little, that wind, generatfrom any dark cloud, and, therefore, the more ed by fermentation is new to you, since it strange to me, I never having seen the like may be every day observed in fermenting libefore. It past about a mile to the leeward quor. You know with what force fermenting of us, and then broke. This was but a small liquors will burst the vessels which contain spout, and not strong nor* lasting; yet I per-| them, if the generated wind have not vent: small vent, or by drawing the cork of a bottle.
and with what force it issues, on giving it a • Probably if it had been lasting, a cloud would have been formed above it. These extracts from Dampier, and, therefore, are inserted entire, for the reader's conReem. in different instances, to favour both opinions, I sideration.
To Peter Collinson. Dr. Boerhaave says, that the steam issuing from fermenting liquors received through a
Account of a Whirlwind in Maryland. very small vent-hole, into the nose, will kill
PAILADELPHIA Aug. 25, 1755, as suddenly and certainly as lightning That As you have my former papers on whirl. air is generated by fermentation, I think you winds, &c. I now send you an account of one will find fully proved in Dr. Hales's Analysis which I had lately an opportunity of seeing of the Air, in his Vegetable Statics. If you and examining myself. have not read the book, you have a new plea-l Being in Maryland, riding with colonel sure to come.
Tasker, and some other gentlemen, to his The solution you give to the objection Icountry seat, where I and my son were enmade from the contrary winds blowing from tertained by that amiable and worthy man the opposite sides of the mountains, from there with great hospitality and kindness, we saw, being eddies, does not please me, because the in the vale below us, a small whirlwind beginextent of these winds is by far too large to be ning in the road, and showing itself by the occasioned by any eddy. It is forty miles dust it raised and contained. It appeared in from New York to our mountains, through the form of a sugar-loaf, spinning on its point, which Hudson's River passes. The river moving up the hill towards us, and enlarging runs twelve miles in the mountains, and from as it came forward. When it passed by us, the north side of the mountains it is about its smaller part near the ground appeared no ninety miles to Albany. I have myself been bigger than a common barrel, widening upon board a vessel more than once, when we wards, it seemed, at forty or fifty feet high, have had a strong northerly wind against us, to be twenty or thirty feet in diameter. The all the way from New York, for two or three rest of the company stood looking after it, but days. We have met vessels from Albany, my curiosity being stronger, I followed it, who assured us, that, on the other side of the riding close by its side, and observed its lickmountains, they had, at the same time, a ing up, in its progress, all the dust that was strong continued southerly wind against them; under its smaller part. As it is a common opiand this frequently happens.
nion that a shot, fired through a water-spout, I have frequently seen, both on the river, will break it, I tried to break this little whirlin places where there could be no eddy-winds wind, by striking my whip frequently through and on the open sea, two vessels sailing with it, but without any effect. Soon after, it quitcontrary winds, within half a mile of each ted the road and took into the woods, growing other; but this happens only in easy winds, every moment larger and stronger, raising, and generally calm in other places near these instead of dust, the old dry leaves with which winds.
the ground was thick covered, and making a You have, no doubt, frequently observed a great noise with them and the branches of the single cloud pass, from which a violent gust trees, bending some tall trees round in a circle of wind issues, but of no great extent. I have swiftly and very surprisingly, though the proobserved such a gust make a lane through gressive motion of the whirl was not so swift the woods, of some miles in length, by laying but that a man on foot might have kept pace the trees flat to the ground, and not above with it, but the circular motion was amazingly eight or ten chains in breadth. Though the rapid. By the leaves it was now filled with, violence of the wind be in the same direction I could plainly perceive that the current of in which the cloud moves and precedes it, yet air they were driven by moved upwards in a wind issues from all sides of it; so that sup- spiral line; and when I saw the passing whirl posing the cloud moves south-easterly, those continue entire, after leaving the trunks and on the north-east side of it feel a south-west bodies of large trees which it had enveloped, wind, and others on the south-west side, a I no longer wondered that my whip had no north-east. And where the cloud passes over effect on it in its smaller state. I accompanied we frequently have a south-east wind from it about three quarters of a mile, till some the hinder part of it, but none violent, except limbs of dead trees, broken off by the whirl, the wind in the direction in which the cloud flying about, and falling near me, made me moves. To show what it is which prevents more apprehensive of danger: and then I stopthe wind from issuing out equally on all sides ped, looking at the top of it as it went on, is not an easy problem to me, and I shall not which was visible, by means of the leaves conattempt to solve it; but when you shall show tained in it, for a very great height above the what it is which restrains the electrical fluid trees. Many of the leaves, as they got loose from spreading itself in the air surrounding it, from the upper and widest part, were scattered when it rushes with great violence through in the wind; but so great was their height in the air along, or in the conductor, for a great the air, that they appeared no bigger than flies. extent in length, then I may hope to explain My son, who was, by this time, come up the other problem, and remove the difficulty with me, followed the whirlwind till it left the we have in conceiving it.
| woods, and crossed an old tobacco-field, where,
finding neither dust nor leaves to take up, it E. of Philadelphia about four hundred miles. gradually became invisible below, as it went This puzzled me, because the storm began away over that field. The course of the ge- with us so soon as to prevent any observation, neral wind then blowing was along with us and being a north-east storm, I imagined it as we travelled, and the progressive motion of must have begun rather sooner in places farthe whirlwind was in a direction nearly oppo- ther to the north-eastward than it did at Phisite, though it did not keep a strait line, nor ladelphia. I therefore mentioned it in a letter was its progressive motion uniform, it making to my brother, who lived at Boston; and he little sallies on either hand as it went, pro- informed me the storm did not begin with ceeding sometimes faster, and sometimes them till near eleven o'clock, so that they had slower, and seeming sometimes for a few a good observation of the eclipse; and upon seconds almost stationary, then starting for comparing all the other accounts I received wards pretty fast again. When we rejoined from the several colonies, of the time of bethe company, they were admiring the vast ginning of the same storm, and since that of height of the leaves now brought by the com- other storms of the same kind, I found the bemon wind, over our heads. These leaves ac- ginning to be always later the farther northcompanied us as we travelled, some falling eastward. I have not my notes with me now and then round about us, and some not here in England, and cannot, from memory, reaching the ground till we had gone near say the proportion of time to distance, but I three miles from the place where we first saw think it is about an hour to every hundred the whirlwind begin. Upon my asking co-miles. lonel Tasker if such whirlwinds were com- From thence I formed an idea of the cause mon in Maryland, he answered pleasantly, of these storms, which I would explain by a No, not at all common, but we got this on familiar instance or two.-Suppose a long purpose to treat Mr. Franklin.-And a very canal of water stopped at the end by a gate. high treat it was too. B. FRANKLIN." The water is quite at rest till the gate is open,
then it begins to move out through the gate ;
the water next the gate is first in motion, and Alexander Small, London.
moves towards the gate; the water next to On the Wurth-east Storms in North America. that first water moves next, and so on suc
, May 12, 1700. cessively, till the water at the head of the caAGREEABLE to your request, I send yon my na) is in motion, which is last of all. In this reasons for thinking that our north-east storms case all the water moves indeed towards the in North America begin first, in point of time, gate, but the successive times of beginning in the south-west parts: that is to say, the motion are the contrary way, viz. from the air in Georgia, the farthest of our colonies to gate backwards to the head of the canal. the south-west, begins to move south-westerly Again, suppose the air in a chamber at rest, before the air of Carolina, which is the next no current through the room till you make a colony north-eastward; the air of Carolina, fire in the chimney. Immediately the air in has the same motion before the air of Vir: the chimney being rarefied by the fire rises; ginia, which lies still more north east-ward; the air next the chimney flows in to supply and so on north-easterly through Pennsylva- its place, moving towards the chimney; and, nia, New York, New England, &c. quite to in consequence, the rest of the air succesNewfoundland.
sively, quite back to the door. Thus to proThese north-east storms are generally very duce our north-east storms, I suppose some violent, continue sometimes two or three days, great heat and rarefaction of the air in or and often do considerable damage in the hår- about the gulph of Mexico; the air thence bours along the coast. They are attended rising has its place supplied by the next more with thick clouds and rain.
northern, cooler, and therefore denser and What first gave me this idea, was the fol- heavier, air; that, being in motion, is followed lowing circumstance. About twenty years by the next more northern air, &c. in a sucago, a few more or less, I cannot from my me- cessive current, to which current our coast mory be certain, we were to have an eclipse of and inland ridge of mountains give the directhe moon at Philadelphia, on a Friday evening, tion of north-east as they lie N. E. and S. W. about nine o'clock. I intended to observe it, This I offer only as an hypothesis to account but was prevented by a north-east storm, which for this particular fact; and perhaps, on farcame on about seven, with thick clouds as ther examination, a better and truer may be usual, that quite obscured the whole hemis- found. I do not suppose all storms generated phere. Yet when the post brought us the in the same manner. Our north-west thunder Boston newspaper, giving an account of the gusts in Amertca, I know are not; but of effects of the same storm in those parts, I them I have written my opinion fully in a found the beginning of the eclipse had been pape! which you have seen. well observed there, though Boston lies N.