On Water-Spouts.

Read at the Royal Society, June 3, 1756.

Boston, October 16, 1752.

Sir,

I find by a word or two in your last[4], that you are willing to be found fault with; which authorises me to let you know what I am at a loss about in your papers, which is only in the article of the water-spout. I am in doubt, whether water in bulk, or even broken into drops, ever ascends into the region of the clouds per vorticem; i. e. whether there be, in reality, what I call a direct water-spout. I make no doubt of direct and inverted whirl-winds; your description of them, and the reason of the thing, are sufficient. I am sensible too, that they are very strong, and often move considerable weights. But I have not met with any historical accounts that seem exact enough to remove my scruples concerning the ascent abovesaid.

Descending spouts (as I take them to be) are many times seen, as I take it, in the calms, between the sea and land trade-winds on the coast of Africa. These contrary winds, or diverging, I can conceive may occasion them, as it were by suction, making a breach in a large cloud. But I imagine they have, at the same time, a tendency to hinder any direct or rising spout, by carrying off the lower part of the atmosphere as fast as it begins to rarefy; and yet spouts are frequent here, which strengthens my opinion, that all of them descend.

But however this be, I cannot conceive a force producible by the rarefication and condensation of our atmosphere, in the circumstances of our globe, capable of carrying water, in large portions, into the region of the clouds. Supposing it to be raised, it would be too heavy to continue the ascent beyond a considerable height, unless parted into small drops; and even then, by its centrifugal force, from the manner of conveyance, it would be flung out of the circle, and fall scattered, like rain.

But I need not expatiate on these matters to you. I have mentioned my objections, and, as truth is my pursuit, shall be glad to be informed. I have seen few accounts of these whirl or eddy winds, and as little of the spouts; and these, especially, lame and poor things to obtain any certainty by. If you know any thing determinate that has been observed, I shall hope to hear from you; as also of any mistake in my thoughts. I have nothing to object to any other part of your suppositions: and as to that of the trade-winds, I believe nobody can.

I am, &c.

P. S.. The figures in the Philosophical Transactions show, by several circumstances, that they all descended, though the relators seemed to think they took up water.