I am persuaded, as well as you, that the sea coal has a vegetable origin, and that it has been formed near the surface of the earth; but, as preceding convulsions of nature had served to bring it very deep in many places, and covered it with many different strata, we are indebted to subsequent convulsions for having brought within our view the extremities of its veins, so as to lead us to penetrate the earth in search of it. I visited last summer a large coal mine at Whitehaven, in Cumberland; and in following the vein and descending by degrees towards the sea, I penetrated below the ocean, where the level of its surface was more than eight hundred fathoms above my head, and the miners assured me that their works extended some miles beyond the place where I then was, continually and gradually descending under the sea. The slate, which forms the roof of this coal mine, is impressed in many places with the figures of leaves and branches of fern, which undoubtedly grew at the surface when the slate was in the state of sand on the banks of the sea. Thus it ap pears that this vein of coal has suffered a prodigious settlement. B. FRANKLIN. I 1 James Barbeu Dubourg, the first French editor of Franklin's works, was an accomplished scholar and naturalist. In 1761, he published a medical periodical; in 1767, he published the Botaniste Francaise in two volumes, judged in its day to be "one of the most agreeable elementary books in the language." He translated Bolingbroke's Letters on History into French, and held at one time intimate relation with their author. He dedicated his Petit Code de la Raison Humaine to Franklin. He was one of the Society of Economistes in France. CCCLXXVI TO JOHN BARTRAM LONDON, II January, 1770. MY EVER DEAR FRIEND:-I received your kind letter of November 29th, with the parcel of seeds, for which I am greatly obliged to you. I cannot make you adequate returns in kind; but I send you, however, some of the true rhubarb seed, which you desire. I had it from Mr. English, who lately received a medal of the Society of Arts for propagating it. I send also some green dry peas, highly esteemed here as the best for making pea soup; and also some Chinese caravances, with Father Navarette's account of the universal use of a cheese made of them in China, which so excited my curiosity, that I caused inquiry to be made of Mr. Flint, who lived many years there, in what manner the cheese was made, and I send you his answer. I have since learned that some runnings of salt (I suppose runnet) is put into water, when the meal is in it, to turn it to curds. I think we have caravances with us, but I know not whether they are the same with these, which actually came from China. They are said to be of great increase. I shall inquire of Mr. Collinson for your Journal. I see that of East Florida is printed with Stork's Account. My love to good Mrs. Bartram and your children. With esteem I am ever, my dear friend, yours affectionately, B. FRANKLIN. CCCLXXVII TO MISS MARY STEVENSON CRAVEN STREET, 22 January, 1770. DEAR POLLY:-I received your favor of Saturday, early this morning, and am, as usual, much obliged by the kind readiness with which you have done what I requested. Your good mother has complained more of her head since you left us than ever before. If she stoops, or looks, or bends her neck downwards, on any occasion, it is with great pain and difficulty that she gets her head up again. She has, therefore, borrowed a breast and neck collar of Mrs. Wilkes, such as misses wear, and now uses it to keep her head up. Mr. Strahan has invited us all to dine there to-morrow, but she has excused herself. Will you come, and go with me? If you cannot well do that, you will at least be with us on Friday. As to my own head, which you so kindly inquire after, its swimming has gradually worn off, and today for the first time I felt nothing of it on getting out of bed. But as this speedy recovery is, as I am fully persuaded, owing to the extreme abstemiousness I have observed for some days past at home, I am not without apprehensions that, being to dine abroad this day, to-morrow, and next day, I may inadvertently bring it on again, if I do not think of my little monitor and guardian angel, and make use of the proper and very pertinent clause she proposes, in my grace. Here comes a morning visitor. Adieu. My best respects to Mrs. Tickell. I am, my dear friend, B. FRANKLIN. yours affectionately, CCCLXXVIII TO NEVIL MASKELYNE, ASTRONOMER ROYAL READ AT THE ROYAL SOCIETY, JANUARY 10, 1771 Craven StreeT, 12 February, 1770. DEAR SIR: I have just received a letter from Mr. Winthrop, dated December 7th, containing the following account, viz.: "On Thursday, the 9th of November, I had an opportunity of observing a transit of Mercury. I had carefully adjusted my clock to the apparent time, by correspondent altitudes of the sun, taken with the quadrant for several days before, and with the same reflecting telescope as I used for the transit of Venus.' I first perceived the little planet making an impression on the sun's limb at 2h 52′ 41′′; and he appeared wholly within at 53′ 58′′ apparent time. The sun set before the planet reached the middle of his course; and for a considerable time before sunset it was so cloudy that the planet could not be discerned. So that I made no observations of consequence, except that of the beginning, at which time the sun was perfectly clear. This transit completes three periods of forty-six years, since the first observation of Gassendi at Paris, in 1631.” I am, Sir, with great esteem, Your most obedient servant, 1 See Philosophical Transactions, Vol. LIX., p. 352. VOL. V.-12. CCCLXXIX TO MICHAEL HILLEGAS LONDON, 17 March, 1770. DEAR SIR:-I received your favor of November 25th, and have made inquiries, as you desired, concerning the copper covering of houses. It has been used here in a few instances only, and the practice does not seem to gain ground. The copper is about the thickness of a common playing-card; and, though a dearer metal than lead, I am told that as less weight serves, on account of its being so much thinner, and as slighter woodwork in the roof is sufficient to support it, the roof is not dearer, on the whole, than one covered with lead. It is said that hail and rain make a disagreeable drumming noise on copper; but this I suppose is rather fancy; for the plates being fastened on the rafters must, in a great measure, deaden such sound. The first cost, whatever it is, will be all, as a copper covering must last for ages; and when the house decays, the plates will still have intrinsic worth. In Russia, I am informed, many houses are covered with plates of iron tinned, such as our tin pots and other vases are made of, laid on over the edges of one another like tiles; and which, it is said, last very long, the tin preserving the iron from much decay by rusting. In France and the Low Countries, I have seen many spouts or pipes for conveying the water down from the roofs of houses, made of the same |