One of the discomforts of colonial times, when large open fireplaces were so common, was a smoky chimney. Franklin’s attention was drawn to this question about the time that he invented the Pennsylvania fireplaces, and he made an exhaustive study of the nature of smoke and heated air. He became very skilful in correcting defects in the chimneys of his friends’ houses, and while he was in England noblemen and distinguished people often sought his aid. It was not, however, until 1785, near the close of his life, that he put his knowledge in writing in a letter to Dr. Ingenhausz, physician to the Emperor of Austria. The letter was published and extensively circulated as the best summary of all that was known on this important question. It is as fresh and interesting to-day as when it was written, and well worth reading, because it explains so charmingly the philosophy of some phenomena of common occurrence which modern books of science are not at much pains to make clear.
His enemies, of course, ridiculed him as a chimney doctor, and his friends have gone to the other extreme in implying that he was the only man in the world who understood the action of heat and smoke, and that, alone and unaided, he delivered mankind from a great destroyer of their domestic comfort. But his letter shows that most of his knowledge and remedies were drawn from the French and Germans. In this, as in many other similar services, he was merely an excellent collector of scattered material, which he summarized so well that it was more available than before. He was by no means the only person in the world who could doctor a chimney; but there were few, if any, who could describe in such beautiful language the way in which it was done.
He invented a stove that would consume its own smoke, taking the principle from a Frenchman who had shown how the flame of a burning substance could be made to draw downward through the fuel, so that the smoke was burnt with the fuel. But the way in which this invention is usually described would lead one to suppose that it was entirely original with Franklin.
He was much interested in agriculture, and was an earnest advocate of mineral manures, encouraged grape culture, and helped to introduce the basket willow and broom-corn into the United States. He at one time owned a farm of three hundred acres near Burlington, New Jersey, where he tried agricultural experiments. He dabbled in medicine, as has been shown, and also wasted time over that ancient delusion, phonetic spelling.
Knowing, as we do, Franklin’s versatility, it is nevertheless somewhat of a surprise to find him venturing into the sphere of music. He is said to have been able to play on the harp, the guitar, and the violin, but probably only in a philosopher’s way and not well on any of them. Some people in England had succeeded in constructing a musical instrument made of glasses, the idea being taken from the pleasant sound produced by passing a wet finger round the brim of a drinking-glass. When in England Franklin was so delighted with these instruments that he set about improving them. He had glasses specially moulded of a bell-like shape and ground with great care until each had its proper note. They were placed in a frame in such a way that they could all be set revolving at once by means of a treadle worked by the foot, and as they revolved they were played by the wet fingers pressed on their brims. He gave the name “Armonica” to his instrument, and describes its tones as “incomparably sweet beyond those of any other.” It is said to have been used in public concerts, and it was one of the curiosities at his famous Craven Street lodging-house in London, where he also had a fine electrical apparatus, and took pleasure in showing his English friends the American experiments of which they had heard so much.
He seems to have studied music with great care as a science, just as he studied the whirlwinds, the smoke, and the lightning; but he was unalterably opposed to the so-called modern music then becoming fashionable, and which is still to a great extent the music of our time. The pleasure derived from it was, he said, not the natural pleasure caused by harmony of sounds, but rather that felt on seeing the surprising feats of tumblers and rope-dancers.
“Many pieces of it are mere compositions of tricks. I have sometimes, at a concert, attended by a common audience, placed myself so as to see all their faces, and observed no signs of pleasure in them during the performance of a great part that was admired by the performers themselves; while a plain old Scotch tune, which they disdained, and could scarcely be prevailed upon to play, gave manifest and general delight.”
In a letter to Lord Kames which has been often quoted he explained at length, and for the most part in very technical language, the reasons for the superiority of the Scotch tunes.
“Farther, when we consider by whom these ancient tunes were composed and how they were first performed we shall see that such harmonical successions of sounds were natural and even necessary in their construction. They were composed by the minstrels of those days to be played on the harp accompanied by the voice. The harp was strung with wire, which gives a sound of long continuance and had no contrivance like that in the modern harpsichord, by which the sound of the preceding could be stopped the moment a succeeding note began. To avoid actual discord, it was therefore necessary that the succeeding emphatic note should be a chord with the preceding, as their sounds must exist at the same time. Hence arose that beauty in those tunes that has so long pleased, and will please forever, though men scarce know why.”
Franklin’s numerous voyages naturally turned his mind to problems of the sea. He pondered much on the question whether the daily motion of the earth from west to east would increase the speed of a ship sailing eastward and retard it on a westward passage. He was not quite sure that the earth’s motion would have such an effect, but he thought it possible.