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.

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.

ticularly be enabled to collect for 1766, annual accounts of the mercurial altitudes in several parts of each of the sixteen continental provinces, for four of which we have them already. But I fear this will fail of success chiefly for want of thermometers, unless the Royal Society should condescend to distribute them over America as they did over Europe and Asia about thirty years ago. Twenty thermometers judiciously distributed, besides those we have here already would answer the end.

Upon reading in the "Annual Register" of 1762, an account of the congelation of mercury, by M. Braunius, with artificial cold in Petersburg, in December, 1759, I ventured yesterday on some of his experiments of refrigeration with common salt, aquafortis, and spirit sal marin., affused upon snow, though with no view of pursuing them to the fixation of mercury, lest I should break my thermometer. thermometer. From Braunius I expected to find the temperature of the snow and the external air the same; but I found it otherwise. Yesterday, from ten in the morning to two in the afternoon, the thermometer in open air abroad was from thirty-seven to forty-three and the snow dissolving apace; during this time for four hours I repeatedly set the tube, or rather the bulb, in snow, covered with it to ten, to twenty, thirty, forty degrees, when on every trial it fell to thirty-two, and there became stationary. And when by artificial cold I had reduced it far below the freezing point, upon removing the tube to pure, fresh, unmixed snow, the mercury constantly rose, and became stationary at thirty-two; yet, removing the snow, it ascended to thirty-seven and beyond. Bringing the thermometer into the house, it rose to fifty; when the bulb being placed in a glass of snow, brought from abroad, the mercury instantly descended from fifty and above to thirty-two, and there was stationary. From thence

I concluded, that, although, below the freezing point, both snow and air might be of the same temperature, yet, when the natural temperature of the air is above freezing, it differs from that of snow, which in this case is always stationary at or about thirty-two.

This morning, the mercury being down to twentyfive abroad, I applied snow to the bulb expecting no alteration, yet it fell half a degree; and at noon there was nearly a degree's difference, the snow a degree colder than the air, though the air held the cold of twenty-eight and a half. But perhaps, after twenty or thirty degrees descent below the freezing point, there may be a coincidence of temperature, as it happened at the Braunian experiment of congealing mercury when he found both snow and air at two hundred and ten of Delisle corresponding to forty below of Fahrenheit, or seventy-two below his freezing point. This little occurrence is new to me, who see few other recent discoveries than what are exhibited in the Magazines. Had we duly the periodical publications of the several Academies of Sciences in Europe, or those of the London Royal Society only (of which we have here only the first ten volumes abridged), I might perhaps save you the trouble of this account.

We have had a severe winter in New England. January 27th, at sunrise, my thermometer stood at five below zero. I am told the same morning at Boston it was nine below. I hope you will not forget to recommend that ingenious and learned gentleman, Professor Winthrop, to the honors of the Royal Society, now that you are in London.*

I am, Sir,

Your most obedient servant,

EZRA STILES.

* Professor Winthrop was chosen a member of the Royal Society not long after the date of this letter. He was proposed by Dr. Franklin, as