settled near you, as is probable, or if you should chance to meet with him anywhere else, I should be extremely obliged to you if you would show him any civility in your power, as he is a stranger, and a most deserving young man. He can inform you fully how printing affairs stand here.

I am greatly indebted to you for your kind offer of serving me. The prices of paper and printing here are now very reasonable. Good printing demy paper (which is the size commonly used) may be had at ten, eleven, or twelve shillings a ream, and other sizes in proportion, viz. crown paper at seven or eight shillings, and pot paper at five or six shillings a ream. Printing one thousand copies of a sheet on a pica letter costs a guinea, and one shilling for every one hundred over that number; and so in proportion, according to the size of the type and page. A pica octavo page contains thirty-eight lines.

I likewise sell all sorts of books, so that if any of your acquaintance want any, I shall be obliged to you if you will direct them to me, in Wine Office Court in Fleet Street. I shall be very well pleased if, in return for your kindness, I could be of any service to you in this place. Meanwhile I shall be extremely glad to keep a friendly correspondence with you, and am, Sir, Your most obedient servant,

WILLIAM STRAHAN.

FROM CADWALLADER COLDEN TO B. FRANKLIN.

Concerning Thoughts on different Species of Matter.— Suggestion for publishing Philosophical Papers.

SIR,

Coldenham, December, 1744.

The season of the year advancing in which our correspondence from this place with New York becomes more uncertain, and my eldest son going now to New York, where he proposes to stay eight or ten days, I hope you will excuse my interrupting you in your business, which I know allows you little time for trifles or

amusements.

In your last you gave me hopes, that you would soon be able to inform me what sentiment Mr. Logan entertains of the Introduction to Fluxions, which was submitted to his perusal. By my last I transmitted to you some thoughts of the different species of matter. As these thoughts are entirely new, and out of the common road of thinking, I have reason not only to be apprehensive that others may not easily receive the conceptions, but that I may have imposed on myself; and it is for this reason, that I have submitted them to Mr. Logan's and your examination. I have already shown it to Mr. Alexander, and some steps I have made in applying these thoughts to the explanation of some pnenomena in which philosophers have hitherto not been able to give satisfaction. He has taken much more pains in the examination, than could have been expected in one so deeply engaged in business; and, however pleasing his sentiments may be to me, I have reason to suspect that he may be biassed by favor to a very long and intimate acquaintance.

I long likewise to know what progress you make in

forming your Society. If it meets with obstruction from the want of proper encouragement or otherwise, I would have you attempt some other method of proceeding in your design; for I shall be very sorry to have it entirely dropped. May you not, as printer, propose to print at certain times a collection of such pieces on the subject of your former proposals, which any shall think proper to send you, and, by way of specimen, to print such papers as your friends may have communicated to you in consequence of your proposals? For this purpose you may desire a subscription by all persons indifferently for your encouragement. I do not propose, that every thing be printed that shall be sent. You may communicate them to the best judges with you of the several subjects on which these papers shall happen to be written, where you are not willing entirely to trust to your own judgment; and, if they be found not fit for the press, you may return them with remarks, or make some excuse for not publishing them. This I expect will in time produce a Society as proposed, by giving men of learning or genius some knowledge of one another, and will avoid some difficulties that always attend the forming of societies in their beginning. Three hundred copies may be sufficient at first, till it be discovered what encouragement the undertaking meets with; and such a number, I cannot doubt, will sell. I am, &c.

CADWALLADER COLDEN.

VOL. VI.

5

AN

ACCOUNT

OF THE NEW-INVENTED

PENNSYLVANIAN FIRE-PLACES;

WHEREIN

THEIR CONSTRUCTION AND MANNER OF OPERATION IS PARTICULARLY EXPLAINED; THEIR ADVANTAGES ABOVE EVERY OTHER METHOD OF WARMING ROOMS DEMONSTRATED; AND ALL OBJECTIONS THAT HAVE BEEN RAISED AGAINST THE USE OF THEM ANSWERED AND OBVIATED. WITH DIRECTIONS FOR PUTTING THEM UP, AND FOR USING THEM TO THE BEST ADVANTAGE. AND A COPPER-PLATE IN WHICH THE SEVERAL PARTS OF THE MACHINE ARE EXACTLY LAID DOWN, FROM A SCALE OF EQUAL PARTS.

PHILADELPHIA ;

PRINTED AND SOLD BY B. Franklin, 1744.

Several editions of this tract have been published, in Europe and America, and sometimes with a wrong date. The above title is a transcript from that of the first edition. In his autobiography he thus speaks of this performance. "Having, in 1742, invented an open stove for the better warming of rooms, and at the same time saving fuel, as the fresh air admitted was warmed in entering, I made a present of the model to Mr. Robert Grace, one of my early friends, who, having an iron furnace, found the casting of the plates for these stoves a profitable thing, as they were growing in demand. To promote that demand, I wrote and published a pamphlet, intitled 'An Account of the new-invented Pennsylvanian Fireplaces,' &c. This pamphlet had a good effect. Governor Thomas was so pleased with the construction of this stove, as described in it, that he offered to give me a patent for the sole vending of them for a term of years; but I declined it from a principle, which has ever weighed with me on such occasions, viz. That, as we enjoy

great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously.

"An ironmonger in London, however, assuming a good deal of my pamphlet, and working it up into his own, and making some small changes in the machine, which rather hurt its operation, got a patent for it there, and made, as I was told, a little fortune by it. And this is not the only instance of patents taken out of my inventions by others, though not always with the same success; which I never contested, as having no desire of profiting by patents myself, and hating disputes. The use of these fire-places in very many houses, both here in Pennsylvania, and the neighbouring states, has been, and is, a great saving of wood to the inhabitants."

In an edition of the author's writings on electrical and philosophical subjects, published in London in the year 1769, the following note is appended to this tract.

"Soon after the foregoing piece was published, some persons in England, in imitation of Mr. Franklin's invention, made what they call Pennsylvanian Fire-places, with Improvements'; the principal of which pretended improvements is, a contraction of the passages in the air-box, originally designed for admitting a quantity of fresh air, and warming it as it entered the room. The contracting these passages gains indeed more room for the grate, but in a great measure defeats their intention. For, if the passages in the air-box do not greatly exceed in dimensions the amount of all the crevices by which cold air can enter the room, they will not considerably prevent, as they were intended to do, the entry of cold air through these crevices.". - EDITOR.

In these northern colonies the inhabitants keep fires to sit by generally seven months in the year; that is, from the beginning of October to the end of April; and, in some winters, near eight months, by taking in part of September and May.

Wood, our common fuel, which within these hundred years might be had at every man's door, must now be fetched near one hundred miles to some towns, and makes a very considerable article in the expense of families.