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other, as one state is easily produced by the other. A strongly positive cloud may drive out of a neighbouring cloud much of its natural quantity of the electric fluid, and, passing by it, leave it in a negative state. In the same way, a strongly negative, cloud may occasion a neighbouring cloud to draw into itself from others an additional quantity, and, passing by it, leave it in a positive state. How these effects may be produced, you will easily conceive, on perusing and considering the experiments in the enclosed paper; and from them too it appears probable, that every change from positive to negative, and from negative to positive, that, during a thunder-gust, we see in the cork balls annexed to the apparatus, is not owing to the presence of clouds in the same state, but often to the absence of positive or negative clouds, that, having just passed, leave the rod in the opposite state. The knocking down of the six men was performed with two of my large jars not fully charged. I laid one end of my discharging-rod upon the head of the first; he laid his hand on the head of the second; the second his hand on the head of the third, and so to the last, who held, in his hand, the chain that was connected with the outside of the jars. When they were thus placed, I applied the other end of my rod to the prime conductor, and they all dropped together. When they got up, they all declared they had not felt any stroke, and wondered how they came to fall; nor did any of them either hear the crack, or see the light of it. You suppose it a dangerous experiment; but I had once suffered the same myself, receiving, by accident, an equal stroke through my head, that struck me down, without hurting me. And I had seen a young woman, that was about to be electrified through the feet (for some indisposition), receive a greater charge through the head, by inadvertently stooping forward to look at the placing of her feet, till her forehead (as she was very tall) came too near my prime conductor; she dropped, but instantly got up again, complaining of nothing. A person so struck, sinks down doubled, or folded together, as it were, the joints losing their strength and stiffness at once, so that he drops on the spot where he stood, instantly, and there is no previous staggering, nor does he ever fall lengthwise. Too great a charge might indeed, kill a man, but I have not yet seen any hurt done by it. It would certainly, as you observe, be the easiest of all deaths.

The experiment you have heard so imperfect an account of, is merely this; I electrified a silver pint can, on an electric stand, and then lowered into it a cork ball, of about an inch diameter, hanging by a silk string, till the cork touched the bottom of the can. The cork was not attracted to the inside of the can, as it would have been to the outside; and, though it touched the bottom, yet, when drawn out, it was not found to be electrified by that touch, as it would have been by touching the outside. The fact is singular. You require the reason; I do not know it. Perhaps you may discover it, and then you will be so good as to communicate it to me.* I find a frank acknowledgment of one's ignorance is, not only the easiest way to get rid of a difficulty, 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 every thing, and so undertake to explain everything, often remain

* Mr. Franklin has since thought, that possibly the mutual repulsion of the inner opposite sides of the electrical can may prevent the accumulating an electric atmosphere upon them, and occasion it to stand chiefly on the outside ; but recommends it to the farther examination of the curious.

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long ignorant of many things that others could and would instruct them in, if they appeared less conceited.

The treatment your friend has met with is so common, that no man, who knows what the world is and ever has been, should expect to escape it. There are everywhere a number of people, who, being totally destitute of any inventive faculty themselves, do not readily conceive that others may possess it; they think of inventions as of miracles; there might be such formerly, but they are ceased. With these, every one who offers a new invention is deemed a pretender; he had it from some other country, or from some book; a man of their own acquaintance, one who has no more sense than themselves, could not possibly, in their opinion, have been the inventor of any thing. They are confirmed, too, in these sentiments, by frequent instances of pretensions to invention, which vanity 'is daily producing. That vanity, too, though an incitement to invention, is, at the same time, the pest of inventors. Jealousy and envy deny the merit or the novelty of your invention ; but vanity, when the novelty and merit are established, claims it for its own. The smaller your invention is, the more mortification you receive in having the credit of it disputed with you by a rival, whom the jealousy and envy of others are ready to support against you, at least so far as to make the point doubtful. It is not in itself of importance enough for a dispute ; no one would think your proofs and reasons worth their attention; and yet, if you do not dispute the point, and demonstrate your right, you not only lose the credit of being in that instance ingenious, but you suffer the disgrace of not being ingenuous; not only of being a plagiary, but of being plagiary for trifles. Had the invention been greater, it would have disgraced you less; for men have not so contemptible an idea of him that robs for gold on the highway, as of him that can pick pockets for half-pence and farthings. Thus, through envy, jealousy, and the vanity of competitors for fame, the origin of many of the most extraordinary inventions, though produced within but a few centuries past, is involved in doubt and uncertainty. We scarce know to whom we are indebted for the compass, and for spectacles, nor have even paper and printing, that record every thing else, been able to preserve with certainty the name and reputation of their inventors. One would not, therefore, of all faculties or qualities of the mind, wish, for a friend or a child, that he should have that of invention. For his attempts to benefit mankind in that way, however well imagined, if they do not succeed, expose him, though very unjustly, to general ridicule and contempt; and, if they do succeed, to envy, robbery, and abuse.

I am, &c.

B. FRANKLIN.

TO M. DALIBARD, AT PARIS, ENCLOSED IN A LETTER

TO PETER COLLINSON.

Beccaria's Work on Electricity. Sentiments of Franklin on pointed Rods, not fully understood in Europe.

- Effect of Lightning on the Church of Newbury, in New England. Remarks on the Subject.

READ AT THE ROYAL SOCIETY, DECEMBER 1874, 1755.

Philadelphia, 29 June, 1755. SIR, • You desire my opinion of Père Beccaria's Italian book.* I have read it with much pleasure, and think

• This work is written conformably to Mr. Franklin's theory, upon artificial and natural electricity, which compose the two parts of it. It was

it one of the best pieces on the subject, that I have seen in any language. Yet, as to the article of Waterspouts, I am not at present of his sentiments; though I must own, with you, that he has handled it very ingeniously. Mr. Collinson has my opinion of whirlwinds and water-spouts at large, written some time since. I know not whether they will be published; if not, I will get them transcribed for your perusal.* It does not appear to me that Père Beccaria doubts of the absolute impermeability of glass in the sense I meant it; for the instances he gives of holes made through glass, by the electric stroke, are such as we have all experienced, and only show, that the electric fluid could not pass without making a hole. In the same manner we say, glass is impermeable to water, and yet a stream from a fire-engine will force through the strongest panes of a window. As to the effect of points in drawing the electric matter from the clouds, and thereby securing buildings, &c., which, you say, he seems to doubt, I must own I think he only speaks modestly and judiciously. I find I have been but partly understood in that matter. I have mentioned it in several of my letters, and, except once, always in the alternative, viz. that pointed rods erected on buildings, and communicating with the moist earth, would either prevent a stroke, or, if not prevented, would conduct it, so as that the building should suffer no damage. Yet, whenever my opinion is examined in Europe, nothing is consid

printed in Italian, at Turin, in quarto, 1753; between the two parts is a letter to the Abbé Nollet, in defence of Mr. Franklin's system. -J. Bevis.

* These papers will be found among the papers on Philosophical Subjects. Beccaria wrote a long letter to Franklin, dated at Turin, December 24th, 1757, giving an account of several experiments made by him in electricity, illustrative of Franklin's principles. The letter, written in Latin, is contained in the Philosophical Transactions, Vol. LI. p. 514; and also in the APPENDIX to this volume. - Epito'r.

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