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with air, it would weigh at least as much less, | less motion, and not suddenly acquiring the as this difference between the weight of that quicker motion of the equatorial earth, apincluded air, and that of water.
pears an east wind blowing westward; the Now although this would do nothing to ac- earth moving from west to east, and slipping count for the dissolution of salt in water, under the air." the smallest lumps of salt being no more In reading
this, two objections occurred to hollow spheres, or any thing of the like na- my mind :—First, that it is said, the tradeture, than the greatest ; yet, perhaps, it might wind doth not blow in the forenoon, but only account for water's rising and being support- in the afternoon. ed in air. For you know that such hollow Secondly, that either the motion of the globules, or bubbles, abound upon the surface northern and southern air towards the equaof the water, which even by the breath of our tor is so slow, as to acquire almost the same mouths, we can cause to quit the water, and motion as the equatorial air when it arrives rise in the air.
there, so that there will be no sensible differThese bubbles I used to suppose to be the ence; or else the motion of the northern and coats of water, containing within them air southern air towards the equator, is quicker, rarefied and expanded with fire, and that and must be sensible; and then the tradetherefore, the more friction and dashing there wind must appear either as a south-east or is upon the surface of the waters, and the north-east wind : south of the equator, a southmore heat and fire, the more they abound. east wind; north of the equator, a north-east.
And I used to think, that although water for the apparent wind must be compounded be specifically heavier than air, yet such a of this motion from north to south, or vice bubble, filled only with fire and very rarefied versa ; and of the difference between its moair, may be lighter than a quantity of com- tion from west to east, and that of the equamon air, of the same cubical dimensions, and, torial air. therefore, ascend; for the rarefied air enclosed, may more fall short of the same bulk of common air, in weight, than the watery coat
Observations in answer to the foregoing. exceeds a like bulk of common air in gravity.
-Read at the Royal Society, Nov. 4, 1758. This was the objection in my mind, though, 1st. The supposing a mutual attraction beI must confess, 1°know not how to account tween the particles of water and air, is not for the watery coat's encompassing the air, introducing a new law of nature; such atas above-mentioned, without allowing the at- tractions taking place in many other known traction between air and water, which the instances. gentleman supposes; so that I do not know 2dly. Water is specifically 850 times heabut that this objection, examined by that sa- vier than air. To render a bubble of water, gacious genius, will be an additional confirm- then, specifically lighter than air, it seems to ation of the hypothesis.
me that it must take up more than 850 times The gentleman observes, " that a certain the space it did before it formed the bubble ; quantity of moisture should be every moment and within the bubble should be either a vadischarged and taken away from the lungs; cuum or air rarefied more than 850 times. If and hence accounts for the suffocating nature a vacuum, would not the bubble be immediateof snuffs of candles, as impregnating the airly crushed by the weight of the atmosphere ? with grease, between which and water there And no heat, we know of, will rarefy air any is a natural repellency; and of air that hath thing near so much; much less the common been frequently breathed in, which is over- heat of the sun, or that of friction by the dashloaded with water, and, for that reason, can ing on the surface of the water : besides, watake no more air. Perhaps the same obser- ter agitated ever so violently produces no heat, vation will account for the suffocating nature as has been found by accurate experiments. of damps in wells.
3dly. A hollow sphere of lead has a firmBut then if the air can support and take off ness and consistency in it, that a hollow but such a proportion of water, and it is ne- sphere or bubble of fluid unfrozen water cancessary that water be so taken off from the not be supposed to have. The lead may suplungs, I queried with myself how it is we can port the pressure of the water it is immerged breathe in an air full of vapours, so full as in, but the bubble could not support the presthat they continually precipitated. Do not we sure of the air, if empty within. see the air overloaded, and casting forth wa 4thly. Was ever a visible bubble seen to ter plentifully, when there is no suffocation? rise in air ? I have made many, when a boy,
The gentleman again observes, “ That the with soap-suds and a tobacco-pipe ; but they air under the equator, and between the tro- all descended when loose from the pipe, though pics, being constantly heated and rarefied by slowly, the air impeding their motion : they the sun, rises; its place is supplied by air from may, indeed, be forced up by a wind from benorthern and southern latitudes, which, com- low, but do not rise, of themselves, though ing from parts where the air and earth had | filled with warm breath.
5thly. The objection relating to our breath Observations on the Meteorological Paper ; ing moist air seems weighty, and must be sent by Cadwallader Colden, of New York, farther considered. The air that has been to B. Franklin.-Read at the Royal Society, breathed has, doubtless, acquired an addition Nov. 4, 1756. of the perspirable matter which nature intends to free the body from, and which would be That power by which the air expands itpernicious if retained and returned into the self, you attribute to a mutual repelling powblood : such air then may become unfit for er in the particles which compose the air, by respiration, as well for that reason, as on ac- which they are separated from each other count of its moisture. Yet I should be glad with some degree of force; now this force, to learn, by some accurate experiment, whe-on this supposition, must not only act when ther a draft of air, two or three times inspir- the particles are in mutual contact, but likeed, and expired, perhaps in a bladder, has, or wise when they are at some distance from has not, acquired more moisture than our each other. How can two bodies, whether common air in the dampest weather. As to they be great or small, act at any distance, the precipitation of water in the air we breathe, whether that distance be small or great, withperhaps it is not always a mark of that air's out something intermediate on which they being overloaded. In the region of the clouds, act? For if any body act on another, at any indeed, the air must be overloaded if it lets distance from it, however small that distance fall its water in drops, which we call rain; but be, without some medium, to continue the acthose drops may fall through a drier air near tion, it must act where it is not, which to me the earth; and accordingly we find that the seems absurd. hygroscope sometimes shows a less degree It seems to me, for the same reason, equalof moisture, during a shower, than at other ly absurd to give a mutual attractive power times when it does not rain at all. The dewy between any other particles supposed to be at dampness, that settles on the insides of our a distance from each other, without any thing walls and wainscots, seems more certainly to intermediate to continue their mutual action. denote an air overloaded with moisture; and I can neither attract nor repel any thing at a yet this is no sure sign : for, after a long distance, without something between my continued cold season, if the air grows sud- hand and that thing, like a string, or a stick; denly warm, the walls, &c. continuing longer nor can I conceive any mutual action without their coldness, will, for some time, condense some middle thing, when the action is continuthe moisture of such air, till they grow ed to some distance. equally warm, and then they condense no The increase of the surface of any body more though the air is not become drier. lessens its weight, both in air, and water, or And, on the other hand, after a warm season, any other fluid, as appears by the slow descent if the air grows cold, though moister than be- of leaf-gold in the air. fore, the dew is not so' apt to gather on the The observation of the different density of walls. A tankard of cold water will, in a the upper and lower air, from heat and cold, hot and dry summer's day, collect a dew on is good, and I do not remember it is taken noits outside ; a tankard of hot water' will col- tice of by others; the consequences also are lect none in the moistest weather.
well drawn; but as to winds, they seem prin6thly. It is, I think, a mistake that the cipally to arise from some other cause. trade-winds blow only in the afternoon. They Winds generally blow from some large tracts blow all day and all night, and all the year of land, and from mountains. Where I live, round, except in some particular places. The on the north side of the mountains, we fresoutherly sea-breezes on your coasts, indeed, quently have a strong southerly wind, when blow chiefly in the afternoon. In the very they have as strong a northerly wind, or calm, long run from the west side of America to on the other side of these mountains. The Guam, among the Philippine Islands, ships continual passing of vessels on Hudson's seldom have occasion to hand their sails, so River, through these mountains, give frequent equal and steady is the gale, and yet they opportunities of observing this. make it in about 60 days, which could not In the spring of the year the sea-wind (by be if the wind blew only in the afternoon. a piercing cold) is always more uneasy to me,
7thly. That really is, which the gentleman accustomed to winds which pass over a tract justly supposes ought to be, on my hypothesis. of land, than the north-west wind. In sailing southward, when you first enter the You have received the common notion of trade-wind, you find it north-east, or there water-spouts, which, from my own ocular abouts, and it gradually grows more east as observation, I am persuaded is a false concep you approach the line. The same observa- tion. In a voyage to the West Indies, I had tion is made of its changing from south-east an opportunity of observing many waterto east gradually, as you come from the south- spouts. One of them passed nearer than ern latitudes to the equator.
thirty or forty yards to the vessel I was in.
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 Answer to the foregoing Observations, by B. near us was an inverted cone, with the tip or apex towards the sea, and reached within
Franklin.-Read at the Royal Society, Noy. 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 not. vessel. I could plainly observe, that a 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 manner 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 đium 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 bet- 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 metal 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- year 1674. One capt. Records of London, quainted with the facts on which it is founded. I 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 thing, had been cast into the sea. at the Royal Society, December 16, 1756. of 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 mizenmast felt the fury of this second blast, and was
Account of another Spout from the same. snapt short off, as the foremast and boltsprit
“ We saw a spout but a small distance from had been before. The mainmast and main- 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 ning. This cloud hovered to the southward reach them. Three men were in the foretop drew to the westward a great pace, at which
of us for the space of three hours, and then when the foremast broke, and one on the boltsprit, 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 fest 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 defective, 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 useful. “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 fly, 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 windward 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 evidown 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 wird, 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 fus, 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;
* Probably if it had been lasting, a cloud would have and with what force it issues on giving it a been formed above it. These extracts from Dampier, and, therefore, are inserted entire, for the reader's con. seem, in different instances, to favour both opinions, sideration.