Volume Ii Part 19 (2/2)
Referring to what Franklin had to say about the action of sunlight in this connection, Arthur Schuster, in his _Some Remarkable Pa.s.sages in the Writings of Benjamin Franklin_, observes: ”Had Franklin used a clean piece of zinc instead of iron shot he might have antic.i.p.ated Hertz's discovery of the action of strong light on the discharge of gases.”
In the course of one of his experiments with an electrified can, Franklin reached the conclusion that a cork, which he had lowered into the can, was not attracted to its internal surface, as it would have been to its external, because the mutual repulsion of the two inner opposite sides of the can might prevent the acc.u.mulation of an electrical atmosphere upon them. From the same experiment, the genius of Henry Cavendish deduced his law that electrical repulsion varies inversely as the square of the distance between the charges.
Instead of declining, it can truly be said that the reputation of Franklin as an electrical investigator and writer has increased with the progress of electrical science. ”We shall, I am sure,” remarks Professor J. J.
Thomson in his _Electricity and Matter_, ”be struck by the similarity between some of the views which we are led to take by the results of the most recent researches, with those enunciated by Franklin in the very infancy of the subject.” Nor should we omit a tribute of Dr. William Garnett, in his _Heroes of Science_, in regard to the statements in Franklin's first letters to Collinson. ”They are,” he says, ”perfectly consistent with the views held by Cavendish and by Clerk Maxwell, and, though the phraseology is not that of modern text-books, the statements themselves can hardly be improved upon to-day.”
If Franklin achieved a higher degree of success in the electrical than in any other scientific field, it was partly, at any rate, because he never again had the opportunity to give such continuous attention to scientific pursuits. To him this was at times a source of very great disappointment.
In one of his letters to Beccaria, dated Sept. 21, 1768, he tells the latter that, preoccupied as he was, he had constantly cherished the hope of returning home, where he could find leisure to resume the philosophical studies that he had shamefully put off from time to time. In a letter, some eleven years later, from Paris, to the same correspondent, he said that he was then prevented by similar distractions from pursuing those studies in which he always found the highest satisfaction, and that he was grown so old as hardly to hope for a return of the leisure and tranquillity, so necessary for philosophical disquisitions. To Sir Joseph Banks he was inspired some years later, by recent astronomical discoveries, made under the patronage of the Royal Society, to write: ”I begin to be almost sorry I was born so soon, since I cannot have the happiness of knowing what will be known 100 years hence,” Indeed, to him, leisure, whether only the seclusion of a thirty-day voyage across the Atlantic, or the final cessation of public life, was but another term for recurrence to his scientific predilections. When he received his leave from Congress to return home from Paris, he wrote joyously to Ingenhousz: ”I shall now be free of Politicks for the Rest of my Life. Welcome again my dear Philosophical Amus.e.m.e.nts.”
There was, to use his own expression, still too much flesh on his bones for his countrymen to allow him any time except for political experiments; but, for proof of the eager interest that he felt in science, and of the prominent position, that he occupied in the scientific world of America, until the last, we need go no further than the fact that, when he died, the meetings of the American Philosophical Society had, for some time, been held at his home in Philadelphia.
How far Franklin might have added to his reputation as a man of science, if he had not become engrossed by political duties and cares, is mere matter of surmise. But there can be no doubt that he was eminently fitted in many respects for scientific inquiry. The scientific temperament he possessed in the very highest degree. He loved the truth too much to allow the workings of human weakness in himself or others to deface its fair features. In reporting to Collinson the electrical achievements, which crowned him with such just renown, he almost invariably spoke of them as if they were the joint achievements of a group of collaborators, of whom he was but one. The generous alacrity, with which he credits to his friends Hopkinson, Kinnersley, or Syng exclusively special discoveries or inventions, made by them, shows conclusively enough how little this was true. There is no reason to believe that his letters to Collinson on electricity would ever have been published but for the unsolicited initiative of Dr. Fothergill and Collinson; or that they would ever have been translated into French but for the spontaneous persuasion that Buffon brought to bear upon D'Alibard.
In a letter to Collinson, after expressing distrust of an hypothesis, advanced by him in former letters to the same correspondent, he declares that he is ashamed to have expressed himself in so positive a manner.
Indeed, he said, he must request Collinson not to expose those letters, or, if he communicated them to any of his friends, at least to conceal the name of the author. His att.i.tude towards his scientific triumphs was, when not that of entire self-effacement, always that of unaffected humility.
I am indebted for your preceding letter [he wrote in his forty-seventh year to John Perkins] but business sometimes obliges one to postpone philosophical amus.e.m.e.nts. Whatever I have wrote of that kind, are really, as they are ent.i.tled, but _Conjectures_ and _Suppositions_; which ought always to give place, when careful observation militates against them. I own I have too strong a penchant to the building of hypotheses; they indulge my natural indolence: I wish I had more of your patience and accuracy in making observations, on which, alone, true philosophy can be founded.
Equally candid and n.o.ble are other observations in a subsequent letter to the same correspondent. Referring to certain objections, made by Perkins to his theory of water spouts, he observed:
Nothing certainly can be more improving to a Searcher into Nature, than Objections judiciously made to his Opinions, taken up perhaps too hastily: For such Objections oblige him to re-study the Point, consider every Circ.u.mstance carefully, compare Facts, make Experiments, weigh Arguments, and be slow in drawing Conclusions. And hence a sure Advantage results; for he either confirms a Truth, before too lightly supported; or discovers an Error, and receives Instruction from the Objector.
In this View I consider the Objections and Remarks you sent me, and thank you for them sincerely.
When he found that he was in error, it cost him no struggle to recant. For a while he believed the sea to be the grand source of lightning, and built up an imposing fabric of conclusions upon the belief; but he did not hesitate afterwards to admit that he had embraced this opinion too hastily.
The same thing is true of the opinion that he held for a time, that the progress of a s.h.i.+p westward, across the Atlantic, is r.e.t.a.r.ded by the diurnal motion of the earth. He supposed that the melting brought about by the action of lightning was a cold fusion until holes burnt in a floor by portions of a molten bell wire convinced him that this was not so.
I was too easily led into that error [he said] by accounts given even in philosophical books, and from remote ages downwards, of melting money in purses, swords in scabbards, etc. without burning the inflammable matters that were so near those melted metals. But men are, in general, such careless observers, that a philosopher can not be too much on his guard in crediting their relations of things extraordinary, and should never build an hypothesis on anything but clear facts and experiments, or it will be in danger of soon falling, as this does, like a house of cards.
In one of his letters to Collinson, he declared that, even though future discoveries should prove that certain conjectures of his were not wholly right, yet they ought in the meantime to be of some use by stirring up the curious to make more experiments and occasion more exact disquisitions.
Following out the same thought in another letter to Collinson he concluded: ”You are at liberty to communicate this paper to whom you please; it being of more importance that knowledge should increase, than that your friend should be thought an accurate philosopher.” In a letter to John Lining, in which he described the experiment from which Cavendish deduced the law of which we have spoken, he observed:
I find a frank acknowledgement of one's ignorance is not only the easiest way to get rid of a dificulty, but the likeliest way to obtain information, and therefore I practise it: I think it an honest policy. Those who affect to be thought to know everything, and so undertake to explain everything often remain long ignorant of many things that others could and would instruct them in, if they appeared less conceited.
The fact is that Franklin had such a keen sense of the dignity and invincibility of truth that he could not be induced to enter into any personal controversy about it. His feelings with regard to such controversies are pointedly expressed in the _Autobiography_ in connection with the attack made by the Abbe Nollet upon his electrical experiments.
I once purpos'd [he said] answering the abbe, and actually began the answer; but, on consideration that my writings contain'd a description of experiments which anyone might repeat and verify, and if not to be verifi'd, could not be defended; or of observations offer'd as conjectures, and not delivered dogmatically, therefore not laying me under any obligation to defend them; and reflecting that a dispute between two persons, writing in different languages, might be lengthened greatly by mistranslations, and thence misconceptions of one another's meaning, much of one of the abbe's letters being founded on an error in the translation, I concluded to let my papers s.h.i.+ft for themselves, believing it was better to spend what time I could spare from public business in making new experiments, than in disputing about those already made.
But in this instance, too, after all, he acted upon the principle, stated in one of his letters to Cadwallader Colden, that he who removes a prejudice, or an error from our minds contributes to their beauty, as he would do to that of our faces who should clear them of a wart or a wen. He went through his experiments again, and satisfied himself that the Abbe had not shaken his positions. At one time, when he was hesitating as to whether he should reply to him, he heard that D'Alibard was preparing to do so.
”Perhaps,” he wrote to his friend, James Bowdoin, ”it may then appear unnecessary for me to do anything farther in it. And will not one's vanity be more gratified in seeing one's adversary confuted by a disciple, than even by one's self?” When Wilson published a pamphlet, contending that lightning rods should be blunt rather than pointed, he simply observed, ”I have not answered it, being averse to Disputes.”
Not only his temperament but his general mental att.i.tude was instinctively scientific. As we have seen, while Whitefield's other auditors were standing mute and spellbound, he was carefully computing the distance that the words of the orator would carry. As we have also seen, when his soldiers were cutting down the giant pines at Gnadenhutten, he had his watch out, deep in his observation of the time that it took them to fell a tree. When his friend, Small, complained of deafness, he wrote to him that he had found by an experiment at midnight that, by putting his thumb and fingers behind his ear, and pressing it out and enlarging it as it were with the hollow of his hand, he could hear the tick of a watch at the distance of forty-five feet which was barely audible at a distance of twenty feet without these aids. Even in his relations to the simplest concerns of life, he had always the eye of a man of science to weight, measure, dimension and distance. If anyone wishes to see how easily he reduced everything to its scientific principles, let him read Franklin's letter to Oliver Neave, who thought that it was too late in life for him to learn to swim. With the confidence bred by a proper sense of the specific gravity of the human body as compared with that of water, Franklin said, there was no reason why a human being should not swim at the first trial.
If Neave would only wade out into a body of water, until it came up to his breast and by a cast of his hand sink an egg to the bottom, between him and the sh.o.r.e, where it would be visible, but could not be reached except by diving, and then endeavor to recover it, he would be surprised to find what a buoyant thing water was.
Franklin also had all the inquisitiveness of a born philosopher. The winds, the birds, the fish, the celestial phenomena brought to his attention on his first voyage from England, the sluggish movement of his s.h.i.+p on his voyage to England in 1757, the temperature and movement of the Gulf Stream, the social and religious characteristics of the Moravians, Indian traits and habits, the still flies in their bath of Madeira wine--all excited his insatiable curiosity, and started him off on interesting trains of observation or reflection.
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