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.

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.

The shoots are sometimes all one way, which, in the last case, they should be. Possibly there may be collections of parti- All these assure me, that there was no cles in our atmosphere, which gradually wind drawing towards them, nor have I found form, by attraction, either similar ones per se, any others that have observed such a wind. or dissimilar particles, by the intervention of It seems plain, by these few instances, that others. But then, whether they shoot or ex-whirlwinds do not always attend spouts; and plode of themselves, or by the approach of that the water really descends in some of some suitable foreign collection, accidentally them. But the following consideration, in brought near by the usual commotions and confirmation of this opinion, may, perhaps, interchanges of our atmosphere, especially render it probable that all the spouts are dewhen the higher and lower regions intermix, scents. before change of winds and weather, I leave. I believe I have now said enough of what I know nothing about. If it should serve for your amusement, or any way oblige you, it is all I aim at, and shall, at your desire, be always ready to say what I think, as I am sure of your candour.

Dr. Perkins to Dr. Franklin. Water-spouts and Whirlwinds-Read 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 descent was certain.

Captain Langstaff, on a voyage to the West

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

The throwing things from it with great | be said to do so (i. e.) to fall, because all the force, instead of carrying them up into the air, is another difference.

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.

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 But, after all, it does not appear that the masses, or a body, upon its falling; but would above-mentioned different degrees of heat and descend in progression according to the seve-cold concur in any region where spouts usural degrees of altitude the different portions ally happen, nor, indeed, in any other. 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

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.

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

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 hollow spheres, or any thing of the like nature, than the greatest; yet, perhaps, it might account for water's rising and being supported in air. For you know that such hollow globules, or bubbles, abound upon the surface of the water, which even by the breath of our mouths, we can cause to quit the water, and rise in the air.

These bubbles I used to suppose to be the coats of water, containing within them air rarefied and expanded with fire, and that therefore, the more friction and dashing there is upon the surface of the waters, and the more heat and fire, the more they abound.

And I used to think, that although water be specifically heavier than air, yet such a bubble, filled only with fire and very rarefied air, may be lighter than a quantity of common air, of the same cubical dimensions, and, therefore, ascend; for the rarefied air enclosed, may more fall short of the same bulk of common air, in weight, than the watery coat

In reading this, two objections occurred to my mind:-First, that it is said, the tradewind doth not blow in the forenoon, but only in the afternoon.

Secondly, that either the motion of the northern and southern air towards the equator is so slow, as to acquire almost the same motion as the equatorial air when it arrives there, so that there will be no sensible difference; or else the motion of the northern and southern air towards the equator, is quicker, and must be sensible; and then the tradewind must appear either as a south-east or north-east wind: south of the equator, a southeast wind; north of the equator, a north-east. For the apparent wind must be compounded of this motion from north to south, or vice versa; and of the difference between its motion from west to east, and that of the equatorial air.

Observations in answer to the foregoing. exceeds a like bulk of common air in gravity: Reid at the Royal Society, Nov. 4, 1756. This was the objection in my mind, though, 1st. THE supposing a mutual attraction beI must confess, I 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 but that this objection, examined by that sagacious genius, will be an additional confirmation of the hypothesis.

2dly. Water is specifically 850 times heavier than air. To render a bubble of water, then, specifically lighter than air, it seems to 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 air ly 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 take no more air. Perhaps the same observation will account for the suffocating nature of damps in wells.

But then if the air can support and take off but such a proportion of water, and it is necessary that water be so taken off from the lungs, I queried with myself how it is we can breathe in an air full of vapours, so full as that they continually precipitated. Do not we see the air overloaded, and casting forth water plentifully, when there is no suffocation? The gentleman again observes, “That the air under the equator, and between the tropics, being constantly heated and rarefied by the sun, rises; its place is supplied by air from northern and southern latitudes, which, coming from parts where the air and earth had

ing on the surface of the water: besides, water agitated ever so violently produces no heat, as has been found by accurate experiments.

3dly. A hollow sphere of lead has a firmness and consistency in it, that a hollow sphere or bubble of fluid unfrozen water cannot be supposed to have. The lead may support the pressure of the water it is immerged in, but the bubble could not support the pressure of the air, if empty within.

Observations on the Meteorological Paper sent by Cadwallader Colden, of New York, to B. Franklin.-Read at the Royal Society, Nov. 4, 1756.

THAT power by which the air expands itself, you attribute to a mutual repelling power in the particles which compose the air, by which they are separated from each other with some degree of force; now this force, on this supposition, must not only act when the particles are in mutual contact, but likewise when they are at some distance from each other. How can two bodies, whether they be great or small, act at any distance, whether that distance be small or great, without something intermediate on which they act? For if any body act on another, at any distance from it, however small that distance be, without some medium, to continue the action, it must act where it is not, which to me seems absurd.

5thly. The objection relating to our breath- | ing moist air seems weighty, and must be farther considered. The air that has been breathed has, doubtless, acquired an addition of the perspirable matter which nature intends to free the body from, and which would be pernicious if retained and returned into the blood such air then may become unfit for respiration, as well for that reason, as on account of its moisture. Yet I should be glad to learn, by some accurate experiment, whether a draft of air, two or three times inspired, and expired, perhaps in a bladder, has, or has not, acquired more moisture than our common air in the dampest weather. As to the precipitation of water in the air we breathe, perhaps it is not always a mark of that air's being overloaded. In the region of the clouds, indeed, the air must be overloaded if it lets fall its water in drops, which we call rain; but those drops may fall through a drier air near the earth; and accordingly we find that the 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 more though the air is not become drier. And, on the other hand, after a warm season, if the air grows cold, though moister than before, the dew is not so apt to gather on the walls. A tankard of cold water will, in a hot and dry summer's day, collect a dew on its outside; a tankard of hot water will collect none in the moistest weather.

6thly. It is, I think, a mistake that the trade-winds blow only in the afternoon. They blow all day and all night, and all the year round, except in some particular places. The southerly sea-breezes on your coasts, indeed, blow chiefly in the afternoon. In the very long run from the west side of America to Guam, among the Philippine Islands, ships seldom have occasion to hand their sails, so equal and steady is the gale, and yet they make it in about 60 days, which could not be if the wind blew only in the afternoon.

The increase of the surface of any body lessens its weight, both in air, and water, or any other fluid, as appears by the slow descent of leaf-gold in the air.

The observation of the different density of the upper and lower air, from heat and cold, is good, and I do not remember it is taken notice of by others; the consequences also are well drawn; but as to winds, they seem principally to arise from some other cause. Winds generally blow from some large tracts of land, and from mountains. Where I live, on the north side of the mountains, we frequently have a strong southerly wind, when they have as strong a northerly wind, or calm, on the other side of these mountains. The continual passing of vessels on Hudson's River, through these mountains, give frequent opportunities of observing this.

In the spring of the year the sea-wind (by a piercing cold) is always more uneasy to me, accustomed to winds which pass over a tract of land, than the north-west wind.

7thly. That really is, which the gentleman justly supposes ought to be, on my hypothesis. 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 concepyou 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.