way, as I think this would argue against the ascent, &c.; but I must pass it, not only for the reason mentioned, but want of room besides.

As to Mr. Stuart's ocular demonstration of the ascent in his great perpendicular spout, the only one it appears in, I say, as to this, what I have written supposes him mistaken, which yet I am far from asserting.

The force of an airy vortex, having less influence on the solid drops of water, than on the interspersed cloudy vapor, makes the last whirl round swifter, though it descend slower; and this might easily deceive, without great care, the most unprejudiced person.

FROM W. MERCER TO B. FRANKLIN.

Description of a Water-Spout at Antigua.

SIR,

READ AT THE ROYAL SOCIETY, June 24th, 1756.

New Brunswick, 11 November, 1752.

I am favored 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 waterspout 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.

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 water-spout 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 straight 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 circle was violently agitated, being whisked about and carried up into the air with great rapidity and noise, and reflected a lustre, as if the sun 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, shingles, staves,* large pieces of the roofs of houses, &c., and one small wooden house it lifted entire from the foundation on which it stood, and carried it to the distance of fourteen feet, where it settled without breaking or oversetting; and, what is remarkable, though the whirlwind moved from west to 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 farther damage done by it. I conclude, wishing you success in your inquiry, and am, &c.

W. M.

* I suppose shingles, staves, timber, and other lumber might be lying in quartities on the wharf, for sale, as brought from the northern colonies. B. F.

TO JOHN PERKINS.

Water-spouts and Whirlwinds compared.

SIR,

READ AT THE ROYAL SOCIETY, JUNE 24TH, 1756.

Philadelphia, 4 February, 1753.

I ought to have written to you long since, in answer to yours of October 16th, concerning the water-spout; but business partly, and partly a desire of procuring further information by inquiry among my sea-faring acquaintance, induced me to postpone writing, from time to time, till I am now almost ashamed to resume the subject, not knowing but you may have forgot what has been said upon it.

Nothing certainly can be more improving to a searcher into nature than objections judiciously made to his opinion, taken up, perhaps, too hastily; for such objections oblige him to re-study the point, consider every circumstance carefully, compare facts, make experiments, weigh arguments, and be slow in drawing conclusions. And hence a sure advantage results; for he either confirms a truth, before too slightly supported, or discovers an error, and receives instruction from the objector.

In this view I consider the objections and remarks you sent me, and thank you for them sincerely; but, how much soever my inclinations lead me to philosophical inquiries, I am so engaged in business, public and private, that those more pleasing pursuits are frequently interrupted, and the chain of thought, necessary to be closely continued in such disquisitions, is so broken and disjointed, that it is with difficulty I satisfy myself in any of them; and I am now not much nearer a

conclusion, in this matter of the spout, than when I first read your letter.

Yet, hoping we may in time sift out the truth between us, I will send you my present thoughts, with some observations on your reasons on the accounts in the Transactions, and on other relations I have met with. Perhaps, while I am writing, some new light may strike me, for I shall now be obliged to consider the subject with a little more attention.

I agree with you, that, by means of a vacuum in a whirlwind, water cannot be supposed to rise in large masses to the region of the clouds; for the pressure of the surrounding atmosphere could not force it up in a continued body or column, to a much greater height than thirty feet. But, if there really is a vacuum in the centre, or near the axis of whirlwinds, then, I think, water may rise in such vacuum to that height, or to a less height, as the vacuum may be less perfect.

I had not read Stuart's account, in the Transactions, for many years, before the receipt of your letter, and had quite forgot it; but now, on viewing his drafts, and considering his descriptions, I think they seem to favor my hypothesis; for he describes and draws columns of water, of various heights, terminating abruptly at the top, exactly as water would do, when forced up by the pressure of the atmosphere into an exhausted tube.

I must, however, no longer call it my hypothesis, since I find Stuart had the same thought, though somewhat obscurely expressed, where he says, "he imagines this phenomenon may be solved by suction (improperly so called), or rather pulsion, as in the application of a cupping-glass to the flesh, the air being first voided by the kindled flax."

In my paper, I supposed a whirlwind and a spout tɔ be the same thing, and to proceed from the same cause,

the only difference between them being, that the one passes over land, the other over water. I find also in the Transactions, that M. de la Pryme was of the same. opinion; for he there describes two spouts, as he calls them, which were seen at different times, at Hatfield, in Yorkshire, whose appearances in the air were the same with those of the spouts at sea, and effects the same with those of real whirlwinds.

Whirlwinds have generally a progressive, as well as a circular motion; so had what is called the spout, at Topsham (see the account of it in the Transactions), which also appears, by its effects described, to have been a real whirlwind. Water-spouts have, also, a progressive motion; this is sometimes greater, and sometimes less; in some violent, in others barely perceivable. The whirlwind at Warrington continued long in Acrement Close.

Whirlwinds generally arise after calms and great heats; the same is observed of water-spouts, which are therefore most frequent in the warm latitudes. The spout that happened in cold weather, in the Downs, described by Mr. Gordon in the Transactions, was, for that reason, thought extraordinary; but he remarks withal, that the weather, though cold when the spout appeared, was soon after much colder; as we find it, commonly, less warm after a whirlwind.

You agree, that the wind blows every way towards a whirlwind, from a large space round. An intelligent whaleman, of Nantucket, informed me, that three of their vessels, which were out in search of whales, happening to be becalmed, lay in sight of each other, at about a league distance, if I remember right, nearly forming a triangle; after some time, a water-spout appeared near the middle of the triangle, when a brisk breeze of wind sprung up, and every vessel made sail;