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nature. But I find it has been long known in the east Bernier, in the account of his travels into India, written above a hundred years since, mentions the custom of travellers carrying their water in flasks covered with wet wrappers, and hung to the pommels of their saddles, so as that the wind might act upon them, and so cool the water. I have also seen a kind of jar for cooling water, made of potter's earth glazed, and so porous that the water gradually oozed through to the surface, supplying water just sufficient for a constant evaporation. I tried it and found the water within much cooler in a few hours. This jar was brought from Egypt.

FROM JOHN CANTON TO B. FRANKLIN.*

The Melting of Metals by Lightning not a cold Fusion. Compressibility of Water and other Fluids.

DEAR SIR,

London, 29 June, 1764.

Your favor of the 14th of March came to my hands the 15th of May last, and gave me great pleasure. The first experiment of Mr. Kinnersley's, which you mention, is, as you observe, a beautiful one to see; and,

Mr. Canton was a very ingenious experimental philosopher, and for many years an active and valuable member of the Royal Society. His papers in the Philosophical Transactions, and other publications, contributed much to the improvement of science. His fondness for electricity was the cause of an intimate friendship between him and Dr. Franklin, which continued till the death of Mr. Canton, on the 22d of March, 1772, in the fifty-fourth year of his age. His most important discovery was that of the compressibility of water, in opposition to the received opinion formed on the celebrated Florentine experiment. For this discovery he was honored by the Royal Society with the Copley Medal, in November, 1765. — EDITOR.

I think, fully proves that the fusion of metals by lightning is not a cold fusion. I have myself several times melted small brass wire by a stroke from your case of bottles, which left a mark where it lay upon the table, and some balls of twice or three times its diameter near the mark, but no part of the wire could be found. At the time of the stroke a great number of sparks, like those from a flint and steel, fly upward and laterally from the place where the wire was laid, and lose their light in the daytime, at the distance of about two or three inches. The diameter of a piece of Mr. Kinnersley's wire, which you were so kind as to send me with the balls, I found to be one part in one hundred and eighty-two of an inch; mine was but one part in three hundred and thirty.

The second of Mr. Kinnersley's experiments, which you relate, and which seems to be a very extraordinary one, I have several times endeavoured to make, but without success. The air with you must certainly be much drier than in England; for I have never observed the enclosed pith-balls to separate by the electrized air of a room, without having first heated the phial, notwithstanding which, they always came together in the phial, before the outward air had lost its electricity, as appears by their separating again when taken out of it. I once electrified the air of my largest room to a considerable degree, and by opening the windows and doors suffered the wind to blow through for about five minutes. I then shut them and examined the air in the room, but found no sign of electricity remaining. This air I electrified to about the same degree as before, and, leaving it confined, it retained a sensible degree of its electricity for more than three quarters of an hour. Hence I entirely agree with you, that the glass in

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Mr. Kinnersley's

experiment received some degree of electricity from the electrized air, and so kept the balls separated after that air was blown away.

I have put your ingenious friend Mr. Bowdoin's telescope into Mr. Nairne's hands, who is making a pedestal for it, which I think will be an improvement of that which Mr. Bowdoin has described in his last letter to me, which you saw. You may depend on my taking all possible care to get it well executed and soon. I find the fitting Dollond's micrometer to the telescope is impracticable.

Since the publication of a short paper in the Transactions, which contains an account of experiments to prove that water is not incompressible, I have discovered a remarkable property belonging to that fluid, which is new to me, though perhaps it may not be so to you. The property I mean is, its being less compressible in summer than in winter. This is contrary to what I find in spirit of wine and oil of olives, which are (as one would expect water to be) more compressible when expanded by heat, and less so when contracted by cold. For, when Fahrenheit's thermometer is at thirty-four degrees and the barometer at twentynine and a half, water is compressed by the weight of the atmosphere forty-nine parts in a million of its whole bulk, and spirit of wine sixty of the same parts. When the thermometer is at fifty degrees, water is compressed forty-six parts and spirit of wine sixty-six parts in a million by the same weight; and, when the thermometer is at sixty-four degrees, this weight will compress water no more than forty-four parts, but it will compress spirit of wine seventy-one of these parts.

As I am not able at present to account for this difference in the compressibility of water myself, I should be very glad to have your thoughts upon it.

The compression by the weight of the atmosphere, and the specific gravity, of the following fluids (which are all that I have yet tried) are set down as they were found in a temperate degree of heat, and when the barometer was at a mean height.

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You will easily perceive that the compressions of these fluids by the same weight are not in the inverse ratio of their densities, or specific gravities, as might be expected. The compression of spirit of wine, for instance, being compared with that of rain water, is greater than in this proportion it ought to be, and the compression of sea water is less.

Mr. Price, Mr. Rose, Mr. Cooper, and the rest of the club, desire their most respectful compliments to you, and very much regret, as I do myself, your leaving England.

I am, with the most sincere regard,

Dear Sir, &c.

JOHN CANTON.

FROM EZRA STILES TO B. FRANKLIN.*

Thermometrical Experiments.

DEAR SIR,

Newport, 20 February, 1765.

If I ask too great a favor of you, to forward the enclosed letter to M. Lomonosow at Petersburg, I leave it entirely with you to suppress it. I have taken the liberty as you see, of asking an answer through your hands. If I make too free a use of your name and friendship, you have it in your power to prevent the abuse. At least, however, give me leave to ask from yourself an account of the discoveries of the Polar voyage, if such an one should be effected. I suppose your Petersburg correspondence is with Epinus and Braunius.

If the Baltic voyages should continue to be prosecuted from America as they are begun, I should be glad of an epistolary connexion at Petersburg. Your residence in London, and even in the world, will not probably continue many years. I had thought to have availed myself of your friendship so far as to have asked your introduction to a correspondence in the philosophic way with some gentleman in London, but this I leave also to your humanity.

When you read the enclosed, you may consider it addressed to yourself, as well as to M. Lomonosow, particularly as to the thermometrical observations here of 1764, which your beneficence has enabled me to make. I have published a request in the prints, that gentlemen of curiosity would furnish themselves with barometers and thermometers, and publish like observations in the respective provinces, that we may par

* Mr. Stiles was at this time a clergyman at Newport, Rhode Island He was afterwards President of Yale College. - EDITOR

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