In regard to water-spouts, having, in a long letter to a gentleman of the same sentiment with you as to their direction, said all that I have to say in support of my opinion; I need not repeat the arguments therein contained, as I intend to send you a copy of it by some other opportunity, for your perusal. I imagine you will find all the appearances you saw, accounted for by my hypothesis. I thank you for communicating the account of them. At present I would only say, that the opinion of winds being generated in clouds by fermentation, is new to me, and I am unacquainted with the facts on which it is founded. I likewise find it difficult to conceive of winds confined in the body of clouds, which I imagine have little more solidity than the fogs on the earth's surface. The objection from the freshness of rain-water is a strong one, but I think I have answered it in the letter above-mentioned, to which I must beg leave, at present, to refer you.
[In Mr. Collinson's edition, there followed here, several extracts, on water-spouts, from Dampier's Voyages, which, as Dampier's book is by no means scarce, and is consequently accessible to the reader, we have omitted, and shall content ourselves with giving the references. The extracts are three. The first is from Vol. I. p. 451. The second and third from Vol. III. p. 182 and 223.]
[Gentleman of New York in Reply.]
Read at the Royal Society, December 6, 1756.
April 2, 1754.
Any knowledge I have of the winds, and other changes which happen in the atmosphere, is so very defective, that it does not deserve the name; neither have I received any satisfaction from the attempts of others on this subject. It deserves then your thoughts, as a subject in which you may distinguish yourself, and be useful.
Your notion of some things conducting heat or cold better than others pleases me, and I wish you may pursue the scent. If I remember right, Dr. Boerhaave, in his chymistry, thinks that heat is propagated by the vibration of a subtle elastic fluid, dispersed through the atmosphere and through all bodies. Sir Isaac Newton says, there are many phenomena to prove the existence of such a fluid; and this opinion has my assent to it. I shall only observe that it is essentially different from that which I call ether; for ether, properly speaking, is neither a fluid nor elastic; its power consists in re-acting any action communicated to it, with the same force it receives the action.
I long to see your explication of water-spouts, but I must tell you before-hand, that it will not be easy for you to convince me that the principal phenomena were not occasioned by a stream of wind issuing with great force, my eyes and ears both concurring to give me this sentiment, I could have no more evidence than to feel the effects, which I had no inclination to do.
It surprises me a little, that wind, generated by fermentation, is new to you, since it may be every day observed in fermenting liquor. You know with what force fermenting liquors will burst the vessels which contain them, if the generated wind have not vent; and with what force it issues on giving it a small vent, or by drawing the cork of a bottle. Dr. Boerhaave says, that the steam issuing from fermenting liquors received through a very small vent-hole, into the nose, will kill as suddenly and certainly as lightning. That air is generated by fermentation, I think you will find fully proved in Dr. Hales's Analysis of the Air, in his Vegetable Statics. If you have not read the book, you have a new pleasure to come.