Stories of Great Scientists - Charles Gibson

Franklin As a Scientist

By the time Benjamin Franklin had reached middle age he had become the best-known and most important man in America; but what interests us at present is his connection with the scientific world.

We have to pass over the greater part of his later life, which was devoted to serving his country as American Minister in London, and later at the Court of France. We must also pass over the important part he played in the transition of America from being a British colony to a self-governing country—the United States of America.

Franklin had been such a constant reader from childhood that he must have come to know something of Science as then understood, but his first serious study of a scientific subject seems to have been on the occasion of a visit paid to Boston by Dr. Spence, of Scotland. That was in the year 1746, at which time Franklin would be about forty years of age. Dr. Spence showed Franklin some of his electrical experiments, and it is supposed that Franklin bought the apparatus from the lecturer at the close of his visit.

Not long afterwards Franklin wrote a paper on "The Sameness of Lightning with Electricity," and this was communicated to the Royal Society of London by one of its members. It is generally stated that the learned members laughed at the idea. But this cannot be quite correct, for the idea of lightning being a huge electric spark was by no means new; it had been suggested a generation earlier, and the sameness had been remarked upon by great men, such as Sir Isaac Newton. Franklin's paper does not set forth the idea as new, but he was the first to propose a method of proving the idea. It was he who suggested means of tapping the supposed electricity of storm-clouds, and bringing it quietly to earth. There is no doubt that it was the boldness of this idea which amused the learned members of the Royal Society, and we can sympathise with them; it would appear to be quite ridiculous.

The gentleman who had communicated Franklin's bold suggestion to the Royal Society had faith in the American statesman's ideas, and he took steps to have it published. It appeared in The Gentleman's Magazine, and also in pamphlet form. A copy of the pamphlet was received by some French Scientists, who followed out the idea on the lines suggested by Franklin. By means of an iron rod placed at a considerable height, they succeeded in drawing electricity from storm-clouds. Before news of this successful experiment had time to reach Franklin, he had become impatient waiting for the completion of a high spire from which he intended making his experiment. In the meantime it occurred to him that a kite might serve to carry up the conductor even to a greater height.

Ben Franklin and lightning


When Franklin and his son went out to try this experiment they must have felt the importance of the trial; it would either confirm or contradict a world-famous suggestion. There were thunder-clouds about, but they passed without giving any sign of electricity at the metal key attached to the end of the string tethering the kite. Franklin held this himself by means of a silk handkerchief which was to act as a non-conductor. He tells us that he had almost despaired of success, when suddenly he observed the loose fibre of the string to move towards an erect position. He then presented his knuckle to the key, and received a strong shock accompanied by a bright spark. His bold idea was proved to be possible. He repeated the experiment, charging a Leyden jar, and making other well-known electrical experiments.

Other experimenters made similar experiments with kites, and with iron rods placed high in the air. No one intended bringing a lightning discharge down the kite string, but it is apparent that they were running some risk. One experimenter, who used a metal wire in place of the wetted kite string, found that with this better conductor he got results which alarmed him; an enormous flash occurred, accompanied with a deafening report, and producing a hole in the ground. The iron rod set up by a Russian professor was struck by lightning, and he being near the free end of it at the moment received a fatal shock.

Franklin suggested the idea of placing pointed conductors on high buildings, leading a wire direct to earth, in order to protect the building against lightning. People were very slow to adopt this novel suggestion, although many of them were very anxious to protect their houses against lightning, some superstitious folk going the length of placing an innocent leek upon the roof as a protection. One of the early lightning conductors had to be removed because the peasants in the neighbourhood insisted that its presence had brought about such a dry summer that their crops had been wasted.

Many years later a Londoner tried to detract from Franklin's lightning conductors by declaring that conductors placed low down were far more effective than if placed high in the air, and further that round knobs were far superior to sharp points. The man who advanced this theory gave a demonstration of some experiments with round knobs at the Pantheon in London. Many people supposed these experiments to support the man's declaration, but some Fellows of the Royal Society came along and showed the matter to be absurd. Had the experimenter been sincere we could owe him no grudge for putting another theory in opposition to Franklin's suggestion, but it is quite evident that he was not honest in the matter, for when three scientists made experiments in the Pantheon to decide the matter, this man, although present, refused to look at them or to attempt any reply.

When word was sent to Franklin concerning this would-be detractor, along with the information that at this man's request the King had got the pointed conductors taken down from his palace and round knobs put up instead, Franklin replied in a very characteristic letter, from which the following is a quotation: "I have never entered into any controversy in defence of my philosophical opinions; I leave them to take their chance in the world. If they are right, truth and experience will support them; if wrong, they ought to be refuted and rejected. Disputes are apt to sour one's temper, and disturb one's quiet. I have no private interest in the reception of my inventions by the world, having never made, nor proposed to make, the least profit by them. The King's changing his pointed conductors for blunt ones is therefore a matter of small importance to me."

We saw in a preceding chapter how Sir Isaac Newton was worried by spending so much time in supporting his philosophical opinions; he would certainly have had more peace of mind had he acted in the same way as Benjamin Franklin, but such an attitude is very difficult to maintain, and Newton felt it a duty to support his theories.

Franklin's great feat in "snatching the lightning from the skies" is the one thing which stands out most prominently in his scientific career, but he did much valuable work to advance the then youthful science of Electricity. He set forth improved theories of electricity; he dispensed with the idea of two separate fluids and devised the single-fluid theory. It was he who applied the terms positive and negative to electrical theory, and he made important discoveries in connection with the Leyden jar. A generation ago we departed from the idea of a subtle fluid, and came to think of electricity as a mere condition of things, but now we are quite convinced that the early idea was correct; indeed, we have proved beyond doubt that electricity is a real, existing thing.

At present we are interested in the man more than in his science; it is sufficient for our purpose to know that he was a hero of Science. Witness the testimony of the illustrious Dr. Joseph Priestley, whose life we shall consider in the succeeding chapter. In his History of Electricity, Priestley wrote of Franklin's work: "Nothing was written upon the subject of Electricity which was more generally read and admired in all parts of Europe."

When Franklin was resident in England as American Minister, he made an extensive tour on the Continent, where he was warmly welcomed by all the men of science. In France he was introduced to Louis XV, and was elected a member of the famous Academy of Science. Previous to this he had been elected an honorary Fellow of the Royal Society of London, and had received honorary degrees from several Universities in Great Britain, as well as in America. In London he was made welcome in the houses of all the great people. He had among his acquaintances such men as Adam Smith, the famous political economist, David Hume, the great historian, and Dr. Joseph Priestley, already mentioned. Franklin was an interested spectator at the Coronation of George III.

The later years of Franklin's life were spent in Paris as an American Minister to the Court of France. It is difficult to realise how a man of his age could get through the work which he did. One extract from his diary will give us some idea of the busy life he led outside of his political duties. At the date of this entry our hero was over seventy-two years of age. "December 13th, 1778. Paris. A man came to tell me he had invented a machine, which would go by itself, without the help of a spring, weight, air, water, or any of the elements, or the labour of man or beast, and with force to work four machines for cutting tobacco; that he had experienced it; would show it me if I would come to his house, and would sell the secret of it for two hundred louis. I doubted it, but I promised to go to him in order to see it.

"A Mons. Coder came with a proposition in writing, to levy six hundred men, to be employed in landing on the coast of England or Scotland to burn and ransom towns and villages, in order to put a stop to the English proceedings in that way in America. I thanked him, and told him I could not approve it, nor had I any money at command for such purposes; moreover, that it would not be permitted by the Government here.

"A man came with a request that I would patronise and recommend to Government an invention he had, whereby a hussar might so conceal his arms and habiliments, with provision for twenty-four hours, as to appear a common traveller; by which means a considerable body might be admitted into a town, one at a time, unsuspected, and afterwards assembling, surprise it. I told him I was not a military man, of course no judge of such matters, and advised him to apply to the Bureau de la Guerre. He said he had no friends, and so could procure no attention. The number of wild schemes proposed to me is so great, and they have hitherto taken so much of my time, that I begin to reject all, though possibly some of them may be worth notice."

Franklin says in another place: "It is amazing the number of legislators that kindly bring me new plans for governing the United States."

"Received a parcel from an unknown philosopher, who submits to my consideration a memoir on the subject of elementary fire, containing experiments in a dark chamber. It seems to be well written, and is in English, with a little tincture of French idiom. I wish to see the experiments, without which I cannot well judge of it."

These were the interruptions in a single forenoon. In reading these extracts from Franklin's journal one wishes he had told us what he found out about the wonderful machine mentioned in the first paragraph. It certainly reads like a fraud. It is interesting to note in connection with the paragraph last quoted, that the unknown philosopher turned out to be no less a personage than the wicked Marat, one of the most infamous characters of the French Revolution, and who was in a great measure responsible for the cruelties and massacres which took place some fourteen years later than the date of Franklin's correspondence with him.

No matter how much one believes in every person having a distinct hobby, one would be willing to allow that such a crowded life as that of Franklin left no room for a hobby. And yet we find that he amused himself sometimes in composing light essays, and printing them himself by means of a small set of types and a press which he kept in his house.

Sometimes Franklin wrote very amusing articles, such as the following, which was addressed to "The Authors of the Journal of Paris," and was signed "A Subscriber." The title of this article, which is given in full in his Memoirs, is "An Economical Project for Diminishing the Cost of Light." In this racy article he explains that he had recently seen a new lamp about which there had been some stir. He says that he suspected that the cost of oil in the new lamp was still proportional to the amount of light given. But he had gone to bed puzzled over the new lamp as he fell asleep. He was wakened by an accidental noise at six o'clock in the morning, and he was surprised to find a flood of bright light in his room. At first he thought that it must be due to some of those new lamps about which he had been puzzling, but on getting up to seek the origin of the light he found that one of his domestics had omitted to close the shutters on his windows and that the light came from the rising sun. He goes on to pretend that he has made a great discovery, and that one scientist stoutly denies the possibility of the light being due to the Sun at so early an hour, which was presumably spring or summer time. This imaginary scientist declares that as there could be no light from the Sun and therefore no light that could enter the room from without, it is evident that the open shutters had merely allowed the darkness to escape. Franklin continues in apparently sincere fashion to dilate upon his great discovery, the conclusion of which is that instead of burning tons of candles at a late hour at night, a much cheaper light was to be got from the early morning sun; just the idea of the recent Daylight Saving Bill. Franklin works out the annual saving per annum that would be possible by such means in Paris. He says that if people find any difficulty in rising at so early an hour, the church bells could all be tolled, and if any people should prove obstinate "let cannon be fired in every street to wake the sluggards effectually." Once more he proclaims his original discovery. "Possibly some may say the Ancients knew that the sun rose at certain hours; I do not dispute it, but it does not follow they knew he gave light as soon as he rose. This is what I claim as my discovery."

[Illustration] from Stories of Great Scientists by Charles Gibson

In looking over Franklin's correspondence I was surprised to come across the following diagram, showing a pair of spectacles arranged for long distance and for reading. In his letter, Franklin explains that he had found two different pairs of spectacles to be very inconvenient, so he had taken them to an optician and got the lenses cut in two and fitted into one frame as shown above. "By this means I wear my spectacles constantly, I have only to move my eyes up or down." We are all familiar with a recent adaptation of the same idea, but it is of interest to find that the idea originated with Benjamin Franklin about one hundred and fifty years ago.

Many eminent scientists were living at the same time as Benjamin Franklin, whose long life closed only ten years before the dawn of the nineteenth century. At Sir Isaac Newton's death Franklin was twenty-one years of age, he was still a young man when our next three heroes (Priestley, Cavendish, and Herschel) were born, and he lived for some time after the births of the three heroes who succeed these in the following pages (Dalton, Young, and Humphry Davy).

While Franklin was in Paris he was one of the scientists appointed by the King of France to investigate the claims of Mesmer, the founder of Mesmerism, then known as Animal Magnetism. Mesmer was a German physician, who claimed to work wonderful cures by means of his newly discovered animal magnetism, a power which he professed to transmit to his patients. Mesmer had met with great applause and profit in Germany, and was beginning to succeed equally well in France when the King caused this scientific inquiry to be made.

The report drawn up by Franklin and the other members of this Commission was not to the liking of Mesmer. It was his custom to use apparatus by which he professed to produce the animal magnetism. One method was to place the patient beneath a mesmeric tree, whereupon he fell into the trance. The report of the investigators stated that it seemed probably that about one person in every ten could be mesmerised, but that the outward magnetism did not exist; it was entirely a case of working upon the imagination of the patient.

Franklin's committee took some of the patients, and after blindfolding them pretended to place them under the mesmeric tree, whereupon they fell into the mesmeric state although the tree was not near them. Then they placed these blindfolded patients directly beneath the tree, but led them to believe that they were not near the tree, and the result was that the tree had no effect. The conclusion of the report was that Mesmer's cures were a fraud except in special cases where imagination was of assistance, and that his declaration of having discovered animal magnetism was a complete fraud; it was simply a reflex action of the mental upon the physical.

Mesmer ultimately fell into disrepute and was forced to retire, but he has had many imitators. The subject reappeared at a later date in its proper form under the title of "Hypnotism."

In dealing with the later part of Franklin's life, chiefly from the Science side, we are apt to overlook how extremely active he was up to the last. He was consulted on every political question which was of importance to America. Science was therefore a hobby with him. Until middle age he was a very active business man, a master-printer, and during the long remainder of his life he was a very busy politician. But Science was more than an ordinary hobby with him; he was a born philosopher, and he has made a lasting name for himself in the Science of Electricity. We have seen how the old gentleman amused himself composing and printing breezy essays, and in addition to this he was a keen chess-player. He tells us that one evening in France he sat at chess from 6 p.m. till sunrise.

When Franklin was eighty years of age he retired from his duties at the Court of France and returned to his native land. He had proposed doing this some years earlier, but those in authority urged him to remain. He has left us an interesting diary of his journey and voyage. He set out from Paris in a litter suspended between two mules with the muleteer riding another. Some days he was on the road so early as 5 a.m., and yet he speaks of the journey as a comfortable one. It was a sort of triumphal march, for he was met at different points by the nobility, military officers, and representatives of learned societies.

On arriving at Havre, after a six days' journey, he had ten days to wait before his ship was ready to sail across the English Channel. After reaching Southampton he had another delay, but we must not think of him as an impatient old man, for he tells us: "I went at noon to bathe in Martin's salt-water hot bath, and floating on my back, fell asleep, and slept near an hour by my watch, without sinking or turning, a thing I never did before, and should hardly have thought possible. Water is the easiest bed that can be made."

At last he set sail for America during the end of July, to land on the other side of the Atlantic in the middle of September, a very slow voyage as things go nowadays, but a whole month shorter than one of his earlier crossings. During that earlier voyage he wrote in his diary: "For a week past we have fed ourselves with the hopes that the change of the moon (which was yesterday) would bring us a fair wind." Imagine being becalmed on the Atlantic for a whole fortnight! We may realise what sort of passenger ships were in use in Franklin's day by an incident which he relates. On one occasion the captain of the ship had been boasting, before leaving port, that his vessel could beat all comers. But after putting out to sea his ship was overtaken by another vessel of similar size. The captain of Franklin's ship, suspecting that the cargo had been placed too far forward, ordered the whole passengers and crew, about forty persons in all, to stand down in the stern of the ship, whereupon she, very quickly overtook her competitor.

Franklin was very silent about his religion, although we have glimpses of his ideas at times, such as in a letter relating to the death of a friend: "Existing here is scarce to be called life; it is rather an embryo state, a preparative to living; a man is not completely born till he is dead."

In a letter to a friend who wrote to Franklin inquiring about his creed, he replied: "It is the first time I have been questioned upon it. I do not take it amiss. Here is my creed. I believe in one God, the Creator of the Universe. That He governs it by His Providence. That He ought to be worshipped. That the most acceptable service we render to Him is doing good to His other children. That the soul of man is immortal, and will be treated with justice in another life respecting its conduct in this."

Franklin lived for some years after his return to America, and passed away at the age of eighty-four. The very great respect in which he was held is attested by the fact that Congress ordered one month's general mourning throughout the United States, while France proclaimed three days' special mourning. Needless to say the epitaph which the youth Benjamin Franklin had written sixty years earlier (see page 145) was not used upon his tombstone, but the words quoted beneath the title of the preceding chapter are to be found upon the statue erected in his memory in Philadelphia:

"He snatched the lightning from the skies and the sceptre from tyrants."