VI Benjamin Franklin
“We call the Americans a nation of inventors,” said Fergus. “How long has this been true?”
“That is a very curious question,” said Uncle Fritz. “You remember we were talking of it before. When I go back to think of the hundred and fifty years before Bunker Hill, I think there must have been a great many inglorious Miltons hidden away in the New England towns. Really, the arts advanced very little between 1630 and 1775. Flint-locks had come in, instead of match-locks. But, actually, the men at Bunker Hill rested over the rail-fence old muskets which had been used in Queen Anne’s time; and to this day a ‘Queen’s arm’ is a provincial phrase, in New England, for one of these old weapons, not yet forgotten. That inability to improve its own condition comes to a people which lets another nation do its manufacturing for it. You see much the same thing in Turkey and French Canada. Just as soon as they were thrown on their own resources here, they began to invent.”
“But,” said Fergus, “there was certainly one great American inventor before that time.”
“You mean Franklin,—the greatest American yet, I suppose, if you mean to measure greatness by intellectual power and intellectual achievement. Yes; Franklin’s great discovery, and the inventions which followed on it, were made twenty-five years and more before Bunker Hill.”
“What is the association between Franklin and Robinson Crusoe?” asked Alice. “I never read of one but I think of the other.”
Uncle Fritz’s whole face beamed with approbation.
“You have started me upon one of my hobbies,” said he; “but I must not ride it too far. Franklin says himself that De Foe’s ‘Essay on Projects’ and Cotton Mather’s ‘Essay to do Good’ were two books which perhaps gave him a turn of thinking which had an influence on some of the events in his after life. And you may notice how an ‘Essay on Projects’ might start his passion for having things done better than in the ways he saw. The books that he was brought up on and with were books of De Foe’s own time,—none of them more popular among reading people of Boston than De Foe’s own books, for De Foe was a great light among their friends in England.
“If Robinson Crusoe, on his second voyage, which was in the year 1718, had run into Boston for supplies, as he thought of doing; and if old Judge Sewall had asked him to dinner,—as he would have been likely to do, for Robinson was a godly old gentleman then, of intelligence and fortune,—if there had been by accident a vacant place at the table at the last moment, Judge Sewall might have sent round to Franklin’s father to ask him to come in. For the elder Franklin, though only a tallow-chandler,—and only Goodman Franklin, not Mr. Franklin,—was a member of the church, well esteemed. He led the singing at the Old South after Judge Sewall’s voice broke down.
“Nay, when one remembers how much Sewall had to do with printing, one might imagine that the boy Ben Franklin should wait at the door with a proof-sheet, and even take off his boy’s hat as Robinson Crusoe came in.”
Here Bedford Long put in a remark:—
“There are things in Robinson Crusoe’s accounts of his experiments in making his pipkins, which ought to bring him into any book of American inventors.”
“I never thought before,” said Fergus, “that De Foe’s experiences in making tiles and tobacco-pipes and drain-pipes fitted him for all that learned discussion of glazing, when Robinson Crusoe makes his pots and pans.”
“Good!” said Uncle Fritz; “that must be so.—Well, as you say, Alice, there are whole sentences in that narrative which you could suppose Franklin wrote, and in his works whole sentences which would fit in closely with De Foe’s writing. The style of the younger man very closely resembles that of the older.”
“And Franklin would have been very much pleased to hear you say so.”
“He was forever inventing,” said Uncle Fritz. “As I said, he was worried unless things could be better done. If he was in a storm, he wanted to still the waves. If the chimney smoked, he wanted to make a better fireplace. If he heard a girl play the musical-glasses, he must have and make a better set.”
“And if the house was struck by lightning, he went out and put up a lightning-rod.”
“He had a little book by which people should make themselves better; for he rightly considered that unless a man could do this, he could make no other improvement of much account.”
And when Uncle Fritz had said this, he found the passage, which he bade John read to them.
Franklin’s Method of Growing Better
“I made a little book in which I allotted a page for each of the virtues. [He had classified the virtues and made a list of thirteen, which will be named below.] I ruled each page with red ink, so as to have seven columns, one for each day of the week, marking each column with a letter for the day. I crossed these columns with thirteen red lines, marking the beginning of each line with the first letter of one of the virtues, on which line and in its proper column I might mark, by a little black spot, every fault I found upon examination to have been committed respecting that virtue upon that day. The thirteen virtues were: 1. Temperance; 2. Silence; 3. Order; 4. Resolution; 5. Frugality; 6. Industry; 7. Sincerity; 8. Justice; 9. Moderation; 10. Cleanliness; 11. Tranquillity; 12. Chastity; 13. Humility. Each of these appears, by its full name or its initial, on every page of the book. But the full name of one only appears on each page.
“My intention being to acquire the habitude of these virtues, I judged it would be well not to distract my attention by attempting the whole at once, but to fix it on one of them at a time, and when I should be master of that, then to proceed to another,—and so on, till I should have gone through the thirteen; and as the previous acquisition might facilitate the acquisition of certain others, I arranged them with that view. Temperance first, as it tends to procure that coolness and clearness of head which is so necessary where constant vigilance has to be kept up, and a guard maintained against the unremitting attraction of ancient habits, and the force of perpetual temptations.”6 And so he goes on to show how Temperance would prepare for Silence, Silence for Order, Order for Resolution, and thus to the end.
Here is the first page of the book, with the marks for the first six of the virtues.
| TEMPERANCE. | |||||||
| Eat not to Dulness. Drink not to Elevation. | |||||||
| S. | M. | T. | W. | Th. | F. | S. | |
| T. | |||||||
| S. | * | * | * | * | |||
| O. | * | * | * | * | * | * | |
| R. | * | * | |||||
| F. | * | * | |||||
| I. | * | ||||||
| S. | |||||||
| J. | |||||||
| M. | |||||||
| C. | |||||||
| T. | |||||||
| C. | |||||||
| H. | |||||||
“I determined to give a week’s strict attention to each of the virtues successively. Thus, in the first week my great guard was to avoid every the least offence against Temperance, leaving the other virtues to their ordinary chance, only marking every evening the faults of the day. Thus, if in the first week I could keep my first line, marked T, clear of spots, I supposed the habit of that virtue so much strengthened, and its opposite weakened, that I might venture extending my attention to include the next, and for the following week keep both lines clear of spots. Proceeding thus to the last, I could go through a course complete in thirteen weeks, and four courses in a year. And like him who having a garden to weed does not attempt to eradicate all the bad herbs at once, which would exceed his reach and his strength, but works on one of the beds at a time, and, having accomplished the first, proceeds to the second, so I should have, I hoped, the encouraging pleasure of seeing on my pages the progress I made in virtue, by clearing successively my lines of their spots, till in the end, by a number of courses, I should be happy in viewing a clean book, after a thirteen weeks’ daily examination.”
Uncle Fritz said that this plan of Franklin’s had been quite a favorite plan of different people at the end of the last century. Richard Lovell Edgeworth, and Mr. Day, and a good many of the other reformers in England, and many in France, really thought that if people only knew what was right they would all begin and do it. They had to learn, by their own experience or somebody’s, that the difficulty was generally deeper down.
There was a man, named Droz, who published a little book called “The Art of being Happy,” with tables on which every night you were to mark yourself, as a school-mistress marks scholars at school, 10 for truth, 3 for temper, 5 for industry, 9 for frugality, and so on.7
“But in the long run,” said Uncle Fritz, “there may be too much self-examination. If you really look up and not down, and look forward and not back, and loyally lend a hand, why, you can afford to look out and not in, in general.”
Fergus brought the talk back to the lightning-rod, and asked where was the earliest hint of it.
The history seems to be this. In the year 1747 a gentleman named Collinson sent to Franklin, from England or Scotland, one of the glass tubes with which people were then trying electrical experiments. Franklin was very much interested. He went on repeating the experiments which had been made in England and on the Continent of Europe. With his general love of society in such things, he had other glass tubes made, and gave them to his friends.
He had one immense advantage over the wise men of England and France, in the superior dryness of our air, which greatly favors such experiments. Almost any one of the young Americans who will read this book has tried the experiment of exciting electricity by shuffling across a Brussels carpet on a dry floor, and then lighting the gas from a gas-jet by the spark. But when you tell an Englishman in London that you have done this, he thinks at first that you are making fun of him. For it is very seldom that the air and the carpet and the floor are all dry enough for the experiment to succeed in England. This difference of climate accounts for the difficulty which the philosophers in England sometimes found in repeating Dr. Franklin’s experiments.
When it came to lightning and experiments about that, he had another very great advantage; for we have many more thunder-storms than they have. In the year 1752, when Mr. Watson was very eager to try the lightning experiments in England, he seems to have had, in all the summer, but two storms of thunder and lightning.
Franklin made his apparatus on a scale which now seems almost gigantic. The “conductor” of an electrical machine such as you will generally see in a college laboratory is seldom more than two feet long. Franklin’s conductor, which was hung by silk from the top of his room, was a cylinder ten feet long and one foot in diameter, covered with gilt paper. In his “Leyden battery” he used five glass jars, as big as large water-pails,—they held nine gallons each. One night he had arranged to kill a turkey by a shock from two of these. He received the shock himself, by accident, and it almost killed him. He had a theory that if turkeys were killed by electricity, the meat would perhaps be more tender.
He acknowledges Mr. Collinson’s present of the glass tube as early as March 28, 1747. On the 11th of July he writes to Collinson that they (“we”) had discovered the power of points to withdraw electricity silently and continuously. On this discovery the lightning-rod is based. He describes this quality, first observed by Mr. Hopkinson, in the following letter:—
“The first is the wonderful effect of pointed bodies, both in drawing off and throwing off the electrical fire.
“For example, place an iron shot, of three or four inches diameter, on the mouth of a clean, dry glass bottle. By a fine silken thread from the ceiling, right over the mouth of the bottle, suspend a small cork ball about the bigness of a marble; the thread of such a length, as that the cork ball may rest against the side of the shot. Electrify the shot, and the ball will be repelled to the distance of four or five inches, more or less, according to the quantity of electricity. When in this state, if you present to the shot the point of a long, slender, sharp bodkin, at six or eight inches distance, the repellency is instantly destroyed, and the cork flies to the shot. A blunt body must be brought within an inch and draw a spark, to produce the same effect. To prove that the electrical fire is drawn off by the point, if you take the blade of the bodkin out of the wooden handle, and fix it in a stick of sealing-wax, and then present it at the distance aforesaid, or if you bring it very near, no such effect follows; but sliding one finger along the wax till you touch the blade, the ball flies to the shot immediately. If you present the point in the dark, you will see, sometimes at a foot distance and more, a light gather upon it, like that of a firefly or glow-worm; the less sharp the point, the nearer you must bring it to observe the light; and at whatever distance you see the light, you may draw off the electrical fire, and destroy the repellency. If a cork ball so suspended be repelled by the tube, and a point be presented quick to it, though at a considerable distance, it is surprising to see how suddenly it flies back to the tube. Points of wood will do near as well as those of iron, provided the wood is not dry; for perfectly dry wood will no more conduct electricity than sealing-wax.
“To show that points will throw off as well as draw off the electrical fire, lay a long, sharp needle upon the shot, and you cannot electrize the shot so as to make it repel the cork ball. Or fix a needle to the end of a suspended gun-barrel or iron rod, so as to point beyond it like a little bayonet; and while it remains there, the gun-barrel or rod cannot, by applying the tube to the other end, be electrized so as to give a spark, the fire continually running out silently at the point. In the dark you may see it make the same appearance as it does in the case before mentioned.”
The next summer, that of 1748, the experiments went so far, that in a letter of Franklin’s to Collinson he proposed the electrical dinner-party, which was such a delight to Harry and Lucy:—
“Chagrined a little that we have been hitherto able to produce nothing in this way of use to mankind, and the hot weather coming on when electrical experiments are not so agreeable, it is proposed to put an end to them for this season, somewhat humorously, in a party of pleasure on the banks of the Skuylkill. Spirits, at the same time, are to be fired by a spark sent from side to side through the river, without any other conductor than the water; an experiment which we some time since performed, to the amazement of many. A turkey is to be killed for our dinner by the electrical shock, and roasted by the electrical jack, before a fire kindled by the electrified bottle; when the healths of all the famous electricians in England, Holland, France, and Germany are to be drank in electrified bumpers, under the discharge of guns from the electrical battery.”
It was in a letter to Collinson of the next year, 1749,—as I suppose, though it is not dated,—that the project of the lightning-rod first appears. It is too long to copy. The paragraphs most important in this view are the following:—
“42. An electrical spark, drawn from an irregular body at some distance, is scarcely ever straight, but shows crooked and waving in the air. So do the flashes of lightning, the clouds being very irregular bodies.
“43. As electrified clouds pass over a country, high hills and high trees, lofty towers, spires, masts of ships, chimneys, &c., as so many prominences and points, draw the electrical fire, and the whole cloud discharges there.
“44. Dangerous, therefore, is it to take shelter under a tree during a thunder-gust. It has been fatal to many, both men and beasts.
“45. It is safer to be in the open field for another reason. When the clothes are wet, if a flash in its way to the ground should strike your head, it may run in the water over the surface of your body; whereas, if your clothes were dry, it would go through the body, because the blood and other humors, containing so much water, are more ready conductors.
“Hence a wet rat cannot be killed by the exploding electrical bottle, when a dry rat may.”
In a letter of 1750, based upon observations made in 1749, Franklin said distinctly, after describing some artificial lightning which he had made:—
“If these things are so, may not the knowledge of this power of points be of use to mankind, in preserving houses, churches, ships, &c., from the stroke of lightning, by directing us to fix, on the highest parts of these edifices, upright rods of iron made sharp as a needle, and gilded to prevent rusting, and from the foot of those rods a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water? Would not these pointed rods probably draw the electrical fire silently out of a cloud before it came nigh enough to strike, and thereby secure us from that most sudden and terrible mischief?
“To determine the question whether the clouds that contain lightning are electrified or not, I would propose an experiment to be tried where it may be done conveniently. On the top of some high tower or steeple, place a kind of sentry-box, big enough to contain a man and an electrical stand. From the middle of the stand let an iron rod rise and pass bending out of the door and then upright twenty or thirty feet, pointed very sharp at the end. If the electrical stand be kept clean and dry, a man standing on it, when such clouds are passing low, might be electrified and afford sparks, the rod drawing fire to him from a cloud. If any danger to the man should be apprehended (though I think there would be none), let him stand on the floor of his box, and now and then bring near to the rod the loop of a wire that has one end fastened to the leads, he holding it by a wax handle; so the sparks, if the rod is electrified, will strike from the rod to the wire, and not affect him.”
The Royal Society “did not think these papers worth printing”!
But, happily, Collinson printed them, and they went all over Europe. The demonstration of the lightning theory, which he had wrought out by his own experiments, was made in France, May 10, 1752; and in Philadelphia by Franklin with the kite in the next month, before he had heard of the success in France. Franklin’s friend Dalibard tried the French experiment. Here is his account of it, as he sent it to the French Academy, as Roxana translated it for the young people:—
I have had perfect success in following out the course indicated by Mr. Franklin.
I had set up at Marly-la-ville, situated six leagues from Paris, in a fine plain at a very elevated level, a round rod of iron, about an inch in diameter, forty feet long, and sharply pointed at its upper extremity. To secure greater fineness at the point, I had it armed with tempered steel, and then burnished, for want of gilding, so as to keep it from rusting; beside that, this iron rod is bent near its lower end into two acute but rounded angles; the first angle is two feet from the lower end, and the second takes a contrary direction at three feet from the first.
Wednesday, the 10th of May, 1752, between two and three in the afternoon, a man named Coiffier, an old dragoon, whom I had intrusted with making the observations in my absence, having heard rather a loud clap of thunder, hastened at once to the machine, took the phial with the wire, presented the loop of the wire to the rod, saw a small bright spark come from it, and heard it crackle. He then drew a second spark, brighter than the first and with a louder sound! He called his neighbors, and sent for the Prior. This gentleman hastened to the spot as fast as he could: the parishioners, seeing the haste of their priest, imagined that poor Coiffier had been killed by the thunder; the alarm was spread in the village; the hail-storm which began did not prevent the flock from following its shepherd. This honest priest approached the machine, and, seeing that there was no danger, went to work himself and drew strong sparks. The cloud from which the storm and hail came was no more than a quarter of an hour in passing directly over our machine, and only this one thunder-clap was heard. As soon as the cloud had passed, and no more sparks were drawn from the iron rod, the Prior of Marly sent off Monsieur Coiffier himself, to bring me the following letter, which he wrote in haste:—
I can now inform you, Sir, of what you are looking for. The experiment is completely successful. To-day, at twenty minutes past two, p. m., the thunder rolled directly over Marly; the clap was rather loud. The desire to oblige you, and my own curiosity, made me leave my arm-chair, where I was occupied in reading. I went to Coiffier’s, who had already sent a child to me, whom I met on the way, to beg me to come. I redoubled my speed through a torrent of hail. When I arrived at the place where the bent rod was set up, I presented the wire, approaching it several times toward the rod. At the distance of an inch and a half, or about that, there came out of the rod a little column of bluish fire smelling of sulphur, which struck the loop of the wire with an extreme and rapid energy, and occasioned a sound like that which might be made by striking on the rod with a key. I repeated the experiment at least six times, in the space of about four minutes, in the presence of several persons; and each experiment which I made lasted the space of a Pater and an Ave. I tried to go on; the action of the fire slackened little by little. I went nearer, and drew nothing more but a few sparks, and at last nothing appeared.
The thunder-clap which caused this event was followed by no other; it all ended in a great quantity of hail. I was so occupied with what I saw at the moment of the experiment, that, having been struck on the arm a little above my elbow, I cannot say whether it was in touching the wire or the rod, I was not even aware of the injury which the blow had given me at the moment when I received it; but as the pain continued, on my return home I uncovered my arm before Coiffier, and we perceived a bruised mark winding round the arm, like what a wire would have made if my bare flesh had been struck by it. As I was going back from Coiffier’s house, I met Monsieur le Vicaire, Monsieur de Milly, and the schoolmaster, to whom I related what had just happened. They all three declared that they smelt an odor of sulphur, which struck them more as they approached me. I carried the same odor home with me, and my servants noticed it without my having said anything to them about it.
This, Monsieur, is an account given in haste, but simple and true, which I attest, and you may depend on my being ready to give evidence of this event on every opportunity. Coiffier was the first who made the experiment, and repeated it several times; it was only on account of what he had seen that he sent to ask me to come. If other witnesses than he and I are necessary, you will find them. Coiffier is in haste to set out.
I am, with respectful consideration, Monsieur,
Yours, &c.,
[Signed] Raulet, Prior of Marly.
May 10, 1752.
“I do not understand,” said Uncle Fritz, “how it happened that no one attempted the experiment before. Franklin had proposed it, very distinctly, in 1750. His friend Dr. Stuber says that he was waiting for the erection of a steeple in Philadelphia. You see, the Quakers, who had founded this city, would have none; they derided what they called ‘steeple-houses,’ little foreseeing what advantage could be drawn from a steeple.
“Meanwhile, in 1750, in October, he did take a view of New York from the ‘Dutch Church steeple,’ which had been struck by lightning in the spring of that year. And here he was able to confirm his theory, by seeing that ‘wire is a good conductor of lightning, as it is of electricity.’”
Musical Glasses
While some of the children were reading these electrical passages, others were turning over the next volume; and to their great delight, they found a picture of the “Musical Glasses.”
“I never had the slightest idea what musical glasses were,” said Jack; and he spouted from Goldsmith the passage from “The Vicar of Wakefield,” where the fashionable ladies from London talked about “Shakspeare and the musical glasses.”
“Were they Dr. Franklin’s musical glasses?”
“I never thought of that,” said Uncle Fritz, well pleased; “but I think it is so. John, look and see what year ‘The Vicar of Wakefield’ was written in.”
John turned to the Cyclopædia, and it proved that Goldsmith wrote that book in 1766.
“And you see,” said Uncle Fritz, “that it was in 1762 that Franklin made his improvement, and that Mr. Puckeridge, the Irish gentleman, had arranged his glasses before. I think you would find that the instrument gradually worked its way into fashion,—slowly, as such things then did in England,—and that Goldsmith knew about Dr. Franklin’s modification.
“I do not now remember any other place where Goldsmith’s life and his touched. But they must have known a great many of the same people. Franklin was all mixed up with the Grub Street people.”
Meanwhile John was following up the matter in the Cyclopædia. But he did not find “Armonica.” Uncle Fritz bade him try in the “H” volume; and there, sure enough, was “Harmonica,” with quite a little history of the invention. Mr. Puckeridge’s fascinating name is there tamed down to Pochrich, probably by some German translator. Dr. Franklin’s instrument is described, and the Cyclopædia man adds:—
“From the effect which it was supposed to have upon the nervous system, it has been suggested that the fingers should not be allowed to come in immediate contact with the glasses, but that the tones should be produced by means of keys, as with a harpsichord. Such an instrument has been made, and called the ‘harpsichord harmonica.’ But these experiments have not produced anything of much value. It is impossible that the delicacy, the swell, and the continuation of the tone should be carried to such perfection as in the simpler method. The harmonica, however much it excels all other instruments in the delicacy and duration of its tones, yet is confined to those of a soft and melancholy character and to slow, solemn movements, and can hardly be combined to advantage with other instruments. In accompanying the human voice it throws it into the shade; and in concerts the other instruments lose in effect, because so far inferior to it in tone. It is therefore best enjoyed by itself, and may produce a charming effect in certain romantic situations.”
“‘Romantic situations’! I should think so,” said Mabel, laughing. “Is not that like the dear German man that wrote this? I see myself lugging my harmonica to the edge of the Kauterskill Falls.”
“How do you know he was a German?” said Alice.
“Because, where John read ‘the simpler method,’ it says ‘the before-mentioned method.’ No Englishman or American in his senses ever said ’before-mentioned’ if he could help himself.”
“Do let us see how dear Dr. Franklin made his machine.”
And the girls unfolded the old-fashioned picture, which is in the sixth volume of Sparks’s Franklin, and read his description of it as he wrote it to Beccaria.
“Is it the Beccaria who did about capital punishment?” asked Fergus.
“No,” Uncle Fritz said, “though they lived at the same time. They were not brothers. The capital-punishment man was the Marquis of Beccaria, and that of makes a great difference in Europe. This man ’did’ electricity, as you would say; and his name is plain Beccaria without any of.”
Then Mabel, commanding silence, at last read the letter to Beccaria. And when she had done, Uncle Fritz said that he should think there might be many a boy or girl who could not buy a piano or what he profanely called a Yang-Yang,—by which he meant a reed organ,—who would like to make a harmonica. The letter, in a part not copied here, tells how to tune the glasses. And any one who lived near a glass-factory, and was on the good-natured side of a good workman, could have the glasses made without much expense.
Letter of Franklin to J. B. Beccaria.
London, July 13, 1762.
Reverend Sir,—... Perhaps, however, it may be agreeable to you, as you live in a musical country, to have an account of the new instrument lately added here to the great number that charming science was already possessed of. As it is an instrument that seems peculiarly adapted to Italian music, especially that of the soft and plaintive kind, I will endeavor to give you such a description of it, and of the manner of constructing it, that you or any of your friends may be enabled to imitate it, if you incline so to do, without being at the expense and trouble I have been to bring it to its present perfection.
You have doubtless heard of the sweet tone that is drawn from a drinking-glass by passing a wet finger round its brim. One Mr. Puckeridge, a gentleman from Ireland, was the first who thought of playing tunes formed of these tones. He collected a number of glasses of different sizes, fixed them near each other on a table, tuned them by putting into them water more or less, as each note required. The tones were brought out by passing his finger round their brims. He was unfortunately burned here, with his instrument, in a fire which consumed the house he lived in. Mr. E. Delaval, a most ingenious member of our Royal Society, made one in imitation of it, with a better form and choice of glasses, which was the first I saw or heard. Being charmed by the sweetness of its tones, and the music he produced from it, I wished only to see the glasses disposed in a more convenient form, and brought together in a narrower compass, so as to admit of a greater number of tones, and all within reach of hand to a person sitting before the instrument, which I accomplished, after various intermediate trials, and less commodious forms, both of glasses and construction, in the following manner.
The glasses are blown as nearly as possible in the form of hemispheres, having each an open neck or socket in the middle. The thickness of the glass near the brim about a tenth of an inch, or hardly quite so much, but thicker as it comes nearer the neck, which in the largest glasses is about an inch deep, and an inch and a half wide within, these dimensions lessening as the glasses themselves diminish in size, except that the neck of the smallest ought not to be shorter than half an inch. The largest glass is nine inches diameter, and the smallest three inches. Between these two are twenty-three different sizes, differing from each other a quarter of an inch in diameter. To make a single instrument there should be at least six glasses blown of each size; and out of this number one may probably pick thirty-seven glasses (which are sufficient for three octaves with all the semitones) that will be each either the note one wants or a little sharper than that note, and all fitting so well into each other as to taper pretty regularly from the largest to the smallest. It is true there are not thirty-seven sizes, but it often happens that two of the same size differ a note or half-note in tone, by reason of a difference in thickness, and these may be placed one in the other without sensibly hurting the regularity of the taper form.
The glasses being thus turned, you are to be provided with a case for them, and a spindle on which they are to be fixed. My case is about three feet long, eleven inches every way wide at the biggest end; for it tapers all the way, to adapt it better to the conical figure of the set of glasses. This case opens in the middle of its height, and the upper part turns up by hinges fixed behind. The spindle, which is of hard iron, lies horizontally from end to end of the box within, exactly in the middle, and is made to turn on brass gudgeons at each end. It is round, an inch in diameter at the thickest end, and tapering to a quarter of an inch at the smallest. A square shank comes from its thickest end through the box, on which shank a wheel is fixed by a screw. This wheel serves as a fly to make the motion equable, when the spindle with the glasses is turned by the foot like a spinning-wheel. My wheel is of mahogany, eighteen inches diameter, and pretty thick, so as to conceal near its circumference about twenty-five pounds of lead. An ivory pin is fixed in the face of this wheel, and about four inches from the axis. Over the neck of this pin is put the loop of the string that comes up from the movable step to give it motion. The case stands on a neat frame with four legs.
To fix the glasses on the spindle, a cork is first to be fitted in each neck pretty tight, and projecting a little without the neck, that the neck of one may not touch the inside of another when put together, for that would make a jarring. These corks are to be perforated with holes of different diameters, so as to suit that part of the spindle on which they are to be fixed. When a glass is put on, by holding it stiffly between both hands, while another turns the spindle, it may be gradually brought to its place. But care must be taken that the hole be not too small, lest, in forcing it up, the neck should split; nor too large, lest the glass, not being firmly fixed, should turn or move on the spindle, so as to touch or jar against its neighboring glass. The glasses are thus placed one in another, the largest on the biggest end of the spindle, which is to the left hand; the neck of this glass is towards the wheel, and the next goes into it in the same position, only about an inch of its brim appearing beyond the brim of the first; thus proceeding, every glass when fixed shows about an inch of its brim (or three quarters of an inch, or half an inch, as they grow smaller) beyond the brim of the glass that contains it; and it is from these exposed parts of each glass that the tone is drawn, by laying a finger upon one of them as the spindle and glasses turn round.
My largest glass is G, a little below the reach of a common voice, and my highest G, including three complete octaves. To distinguish the glasses the more readily to the eye, I have painted the apparent parts of the glasses withinside, every semitone white, and the other notes of the octave with the seven prismatic colors,—viz., C, red; D, orange; E, yellow; F, green; G, blue; A, indigo; B, purple; and C, red again,—so that glasses of the same color (the white excepted) are always octaves to each other.
This instrument is played upon by sitting before the middle of the set of glasses, as before the keys of a harpsichord, turning them with the foot, and wetting them now and then with a sponge and clean water. The fingers should be first a little soaked in water, and quite free from all greasiness; a little fine chalk upon them is sometimes useful, to make them catch the glass and bring out the tone more readily. Both hands are used, by which means different parts are played together. Observe that the tones are best brought out when the glasses turn from the ends of the fingers, not when they turn to them.
The advantages of this instrument are, that its tones are incomparably sweet, beyond those of any other; that they may be swelled and softened at pleasure by stronger or weaker pressure of the finger, and continued to any length; and that the instrument, being once well tuned, never again wants tuning.
In honor of your musical language, I have borrowed from it the name of this instrument, calling it the Armonica.
With great respect and esteem, I am, &c.,
B. Franklin.