FROM M. DALIBARD TO B. FRANKLIN. TRANSLATION. Intelligence on Philosophical Subjects. MY DEAR FRIEND, Paris, 31 March, 1754. I received on the 15th of January last, your obliging letter of October 28th. I did not reply to it immediately, because I thought it best to wait for what you were to send me by the next vessel, which you informed me would sail eight or ten days later. I have waited till this time, without having received any thing but a small parcel of seeds, and a very kind letter from our respected friend, Mr. Bartram. Our worthy correspondent, Mr. Collinson, forwarded it to me by a mutual friend, who furnishes me with another opportunity of sending letters to England. It is only two days since I received Mr. Bartram's packet, and I beg you will have the kindness to send him my answer. I learned, a short time before I received your last letter, that the vessel, on board which was the parcel of books which I sent to Mr. Collinson for you, had been lost at the mouth of the Thames. I regretted extremely this loss, which it is not possible for me fully to repair, as there were some books among them, which I had received from Germany, and which I cannot obtain again here. I intend to send you, by the first opportunity I can find direct to London, the books for which you asked me, namely, the four volumes of Buffon's Natural History, two copies of your Letters, and the Maps of North and South America by Delisle and Buache. To these I shall add two copies of my Flora Parisiensis; and if the translation, which I am causing to be made, of a work on Electricity by M. Beccaria, presented to me by the author, is finished, I shall send you the original Italian. The hope of soon receiving what you announced o me in your letter of October 28th, has caused me to delay the new edition of your Letters on Electricity till this time. Besides this, urgent business of various kinds has so occupied my time during the whole of the last winter, that I have been able to devote but few moments to philosophical studies. I have regretted, and still regret this the more, as we have had in this country the finest weather for electrical experiments. I have not been able to procure a sulphur globe, such as I proposed to have, because I have not had time to be present while it was making. It is owing to this same want of time, that the attempt to make my electrometer has not yet proved successful. But I have not given up the one or the other. I hope to give my attention to them shortly, as soon as I shall be somewhat relieved from the pressure of business; and I shall again devote myself to electricity, which still seems to me worthy of the most diligent study. All our philosophical friends, Messrs. Buffon, Fonferrière, Marty, &c., charge me to make you their best compliments, and M. Dubourg also. We are all waiting with the greatest eagerness to hear from you. I beg that you will let me have letters as soon and often as possible. Your name is venerated in this country as it deserves to be. There are but few electricians, like the Abbé Nollet, whose jealousy is excited by the honor your discoveries have obtained. With great respect and esteem, DALIBARD FROM CADWALLADER COLDEN TO B. FRANKLIN. Water-Spouts. Wind generated by Fermentation. Winds blowing in contrary Directions. READ AT THE ROYAL SOCIETY, DECEMBER 6TH, 1756. 2 April, 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 Chemistry, thinks that heat is propagated by the vibration of a subtile, 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 reacting 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 beforehand, 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. Hale's Analysis of the Air, in his "Vegetable Statics." If you have not read the book, you have a new pleasure to come. . The solution you give to the objection I made from the contrary winds blowing from the opposite sides of the mountains, from their being eddies, does not please me, because the extent of these winds is by far too large to be occasioned by any eddy. It is forty miles from New York to our mountains, through which Hudson's River passes. The river runs twelve miles in the mountains, and from the north side of the mountains it is about ninety miles to Albany. I have myself been on board a vessel more than once, when we have had a strong northerly wind against us, all the way from New York, for two or three days. We have met vessels from Albany, who assured us that, on the other side of the mountains, they had, at the same time, a strong, continued southerly wind against them; and this frequently happens. I have frequently seen, both on the river, in places where there could be no eddy-winds, and on the open sea, two vessels sailing with contrary winds, within half a mile of each other; but this happens only in easy winds, and generally calm in other places near these winds. You have, no doubt, frequently observed a single cloud pass, from which a violent gust of wind issues, but of no great extent. I have observed such a gust make a lane through the woods, of some miles in length, by laying the trees flat to the ground, and not above eight or ten chains in breadth. Though the violence of the wind be in the same direction in which the cloud moves and precedes it, yet wind issues from all sides of it; so that, supposing the cloud moves southeasterly, those on the northeast side of it feel a southwest wind, and others on the southwest side, a northeast. And where the cloud passes over, we frequently have a southeast wind from the hinder part of it, but none violent, except the wind in the direction in which the cloud moves. To show what it is which prevents the wind from issuing out equally on all sides, is not an easy problem to me, and I shall not attempt to solve it; but when you shall show what it is which restrains the electrical fluid from spreading itself into the air surrounding it, when it rushes with great violence through the air along, or in the conductor, for a great extent in length, then I may hope to explain the other problem, and remove the difficulty we have in conceiving it. FROM CADWALLADER COLDEN TO B. FRANKLIN. New Theory of the Motion of the Planets best suited for calculating Astronomical Tables. Abbé Nollet's Book. DEAR SIR, Coldenham, 2 April, 1754. I should have acknowledged your favor of the 1st of January sooner, if you had not at the same time told |