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de cet événement dans toutes les occasions. I by wetting the apparatus, the electricity was Coiffier a été le premier qui a fait l'expéri- dissipated too soon to be perceived upon ence et l'a répétée plusieurs fois ; ce n'est touching those parts of the apparatus, which qu' à l'occasion de ce qu'il a vu qu'il m'a served to conduct it. This, I say, in general envoyé prier de venir. S'il étoit besoin d'au- prevented our verifying Mr. Franklin's hypotres temoins que de lui et de moi, vous les thesis: but our worthy brother, Mr. Canton, trouveriez. Coiffier presse pour partir. was more fortunate, I take the liberty, there

Je suis avec une respectueuse considéra- fore, of laying before you an extract of a lettion, Monsieur, votre, et signė RAULET, ter, which I received from that gentleman, Prieur de Marly. 10 Mai, 1752.

dated from Spital-square, July 21, 1752. "On voit, par le détail de cette lettre, que “ I had yesterday, about five in the afterle fait est assez bien constaté pour ne laisser noon, an opportunity of trying Mr. Franklin's aucun doute à ce sujet. Le porteur m'a as experiment of extracting the electrical fire curé de vive voix qu'il avoit tiré pendant près from the clouds; and succeeded, by means d'un quart-d'heure avant que M. le Prieur ar- of a tin tube, between three and four feet ia rivât, en présence de cinq ou șix personnes, length, fixed to the top of a glass, one of des étincelles plus fortes et plus bruyantes about eighteen inches. To the upper end of que celles dont il est parlé dans la lettre. the tin tube, which was not so high as a stack Ces premieres personnes arrivant successive- of chimnies on the same house, I fastened ment, n'osient approcher qu'à 10 ou 12 pas de three needles with some wire ; and to the la machine; et à cette distance, malgré le lower end was soldered a tin cover, to keep plein soleil, ils voyoient les étincelles et en- the rain from the glass tube, which was set tendoient le bruit. ....

upright in a block of wood. I attended this “ Il résulte de toutes les expériences et ob- apparatus as soon after the thunder began as servations que j'ai rapportées dans ce mé- possible, but did not find it in the least elecmoire, et surtout de la derniere expérience, trified, till between the third and fourth clap; faite à Marly-la-ville, que la matière du ton- when applying my knuckle to the edge of nerre est incontestablement la même que celle the cover, I felt and heard an electrical spark; de l'électricité. L'idée qu'en a eue M. Frank- and approaching it a second time, I received lin cesse d'être une conjecture: la voilà de- the spark at the distance of about half an venue une réalité, et j'ose croire que plus on inch, and saw it distinctly. This I repeated approfondira tout ce qu'il a publié sur l'élec- four or five times in the space of a minute, tricité, plus on reconnoîtra combien la phy- but the sparks grew weaker and weaker; sique lui est redevable pour cette partie.” and in less than two minutes the tin tube did

not appear to be electrified at all. The rain

continued during the thunder, but was consiLetter of Mr. W. Watson, F. R. S. to the derably abated at the time of making the ex

Royal Society, concerning the Electrical periment.” Thus far Mr. Canton. Experiments in England upon Thunder Mr. Wilson likewise of the Society, to Clouds.--Read Dec. 1752. Trans. Vol. whom we are much obliged for the trouble he

has taken in these pursuits, had an opportuAFTER the communications, which we have nity of verifying Mr. Franklin's hypothesis. received from several of our correspondents in He informed me, by a letter from near different parts of the continent, acquainting Chelmsford, in Essex, dated August 12, 1752, us with the success of their experiments last that, on that day about noon, he perceived summer, in endeavouring to extract the elec- several electrical snaps, during, or rather at tricity from the atmosphere during a thunder- the end of a thunder-storm, from no other apstorm, in consequence of Mr. Franklin's hypo- paratus than an iron curtain rod, one end of thesis, it may be thought extraordinary, that which he put into the neck of a glass phial, and no accounts have been yet laid before you of held this phial in his hand. To the other end our success here from the same experiments

. of the iron he fastened three needles with That no want of attention, therefore, may be some silk. This phial, supporting the rod, he attributed to those here, who have been hi- held in one hand, and drew snap from the therto conversant in these inquiries, I thought rod with a finger of his other. This experiproper to apprize you, that, though several ment was not made upon any eminence, but members of the Royal Society, as well as my- in the garden of a gentleman, at whose house self, did, upon the first advices from France, he then was. prepare and set up the necessary apparatus Dr. Bevis observed, at Mr. Cave's, at St. for this purpose, we were defeated in our ex. John's Gate, nearly the same phenomena as pectations, from the uncommon coolness and Mr. Canton, of which an account has been aldampness of the air here, during the whole ready laid before the public.

We had only at London one thun Trifling as the effects here mentioned are, der-storm; viz. on July 20; and then the when compared with those which we have thunder was accompanied with rain ; so that, received from Paris and Berlin, they are the

xlvii.

summer.

and am,

only ones, that the last summer here has ger to it, a spark will issue from it to your finproduced; and as they were made by persons ger: now when a phial, prepared for the worthy of credit, they tend to establish the Leyden experiment, is hung to the gun-barauthenticity of those transmitted from our rel or prime conductor, and you turn the correspondents.

globe in order to charge it; as soon as the I flatter myself, that this short account of electric matter is excited, you can observe a these matters will not be disagreeable to you; spark to issue from the external surface of the

W. WATSON.* phial to your finger, which, Mr. Franklin says,

is the natural electric matter of the glass

driven out by that received by the inner surRemarks on the Abbé Nollets Letters to Ben face from the conductor. If it be only drawn jamin Franklin, of Philadelphia, on elec-out by sparks, a vast number of them may tricity: by David Colden, of New York.

be drawn; but if you take hold of the exter

nal surface with your hand, the phial will COLDENHAM, in New York, Dec. 4, 1753. soon receive all the electric matter it is capaIn considering the Abbé Nollet's Letters ble of, and the outside will then be entirely to Mr. Franklin, I am obliged to pass by all destitute of its electric matter, and no spark the experiments which are made with, or in, can be drawn from it by the finger : here then bottles hermetically sealed, or exhausted of is a want of that effect, which all bodies chargair ; because, not being able to repeat the ex

ed with electricity have. Some of the effects periments, I could not second any thing which of an electric body, which I suppose the Abbe occurs to me thereon, by experimental proof. has observed in the exterior surface of a Wherefore, the first point wherein I can dare charged phial, are, that all light bodies are atto give my opinion, is in the Abbé's 4th tracted by it. This is an effect which I have letter, where he undertakes to prove, that constantly observed, but do not think that it the electric matter passes from one surface to proceeds from an attractive quality in the exanother through the entire thickness of the terior surface of the phial, but in those light glass: he takes Mr. Franklin's experiment of bodies themselves, which seem to be attractthe magical picture, and writes thus of it: ed by the phial. It is a constant observation, " When you electrise a pane of glass coated that when one body has a greater charge of on both sides with metal, it is evident that electric matter in it than another (that is in whatever is placed on the side opposite to proportion to the quantity they will hold) this that which receives the electricity from the body will attract that which has less : now, I conductor, receives also an evident electrical suppose, and it is a part of Mr. Franklin's virtue.” Which Mr. Franklin says, is that system, that all those light bodies which apequal quantity of electric matter, driven out pear to be attracted, have more electric matof this side, by what is received from the con- ter in them than the external surface of the ductor on the other side; and which will con- phial has, wherefore they endeavour to attinue to give an electrical virtue to any thing tract the phial to them, which is too heavy to in contact with it, till it is entirely discharg. be moved by the small degree of force they ed of its electrical fire. To which the Abbé exert, and yet being greater than their own thus objects: “Tell me (says he,) I pray you, weight, moves them to the phial. The folhow much time is necessary for this pretend- lowing experiment will help the imagination ed discharge? I can assure you, that after in conceiving this. Suspend a cork ball, or having maintained the electrisation for hours, a feather, by a silk thread, and electrise it; this surface, which ought, as it seems to me, then bring this ball nigh to any fixed body, to be entirely discharged of its electrical mat- and it will appear to be attracted by that body, ter, considering either the vast number of for it will fly to it: now, by the consent of sparks that were drawn from it, or the time electricians, the attractive cause is in the ball that this matter had been exposed to the ac- itself, and not in the fixed body to which it tion of the expulsive cause; this surface, I flies: this is a similar case with the apparent say, appeared rather better electrised there-attraction of light bodies, to the external surby, and more proper to produce all the effects face of a charged phial. of an actual electric body."

The Abbé says, “ that he can electrise The Abbé does not tell us what those effects a hundred men, standing on wax, if they were, all the effects I could never observe, hold hands, and if one of them touch one of and those that are to be observed can easily these surfaces (the exterior) with the end of be accounted for, by supposing that side to be his finger:" this I know he can, while the entirely destitute of electric matter. The phial is charging, but after the phial is chargmost sensible effect of a body charged with ed. I am as certain he cannot: that is, hang a electricity is, that when you present your fin- phial, prepared for the Leyden experiment, to

the conductor, and let a man, standing on the * This is the sometime celebrated Watson, bishop of the globe is turned, till the electric matter

floor, touch the coating with his finger, while Landaft,

1

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spews out of the hook of the phial, or some give; neither can it give as much to the
part of the conductor, which I take to be the coating of the other phial as it is ready to take
certainest sign that the phial has received all when one is only applied to me: but when
the electric matter it can: after this appears, both are applied, the coating takes from me
let the man, who before stood on the floor, what the hook gives: thus I receive the fire
step on a cake of wax, where he may stand from the first phial at B, the exterior surface
for hours, and the globe all that time turned, of which is supplied from the hand at A; I
and yet have no appearance of being elec- give the fire to the second phial at C, whose
trised. After the electric matter was spewed interior surface is discharged by the hand at
out as above from the hook of the phial pre- D. This discharge at D may be made evi-
pared for the Leyden experiment, I hung ano- dent by receiving that fire into the hook of a
ther phial, in like manner prepared, to a hook third phial, which is done thus: in place of
fixed in the coating of the first, and held this taking the hook of the second phial in your
other phial in my hand; now if there was hand, run the wire of a third phial, prepared
any electric matter transmitted through the as for the Leyden experiment, through it, and
glass of the first phial, the second one would hold this third phial in your hand, the second
certainly receive and collect it; but having one hanging to it, by tạe ends of the hooks
kept the phials in this situation for a consi- run through each other: when the experi-
derable time, during which the globe was con- ment is performed, this third phial receives
tinually turned, I could not perceive that the the fire at D, and will be charged.
second phial was in the least charged, for
when I touched the hook with my finger, as

D
in the Leyden experiment, I did not feel the
least commotion, nor perceive any spark to
issue from the hook,

I likewise made the following experiment: having charged two phials (prepared for the B Leyden experiment) through their hooks; two persons took each one of these phials in his hand; one held his phial by the coating, the other by the hook, which he could do by

1 removing the communication from the bottom before he took hold of the hook. These persons placed themselves one on each side of me, while I stood on a cake of wax, and took hold of the hook of that phial which was held by its coating (upon which a spark issued, When this experiment is considered, I but the phial was not discharged, as I stood think, it must fully prove that the exterior on wax) keeping hold of the hook, I touched surface of a charged phial wants electric matthe coating of the phial that was held by its ter, while the inner surface has an excess of hook with my other hand, upon which there it. One thing more worthy of notice in this was a large spark to be seen between my experiment is, that I feel no commotion or finger and the coating, and both phials were shock in my arms, though so great a quantity instantly discharged. If the Abbé's opinion of electric matter passes them instantaneously. be right, that the exterior surface, communi- I only feel a pricking in the ends of my fingers. cating with the coating, is charged, as well as This makes me think the Abbé has mistook, the interior, communicating with the hook; when he says, that there is no difference behow can I, who stand on wax, discharge both tween the shock felt in performing the Leythese phials, when it is well known I could den experiment, and the pricking felt on drawnot discharge one of them singly? Nay, sup- ing simple sparks, except that of greater to pose I have drawn the electric matter from less. In the last experiment, as much elecboth of them, what becomes of it? For I ap- tric matter went through my arms, as would pear to have no additional quantity in me have given me a very sensible shock, had when the experiment is over, and I have not there been an immediate communication, by stirred off the wax: wherefore this experiment my arms, from the hook to the coating of the fully convinces me, that the exterior surface same phial; because when it was taken into is not charged; and not only so, but that it a third phial, and that phial discharged singly wants as much electric matter as the inner through my arms, it gave me a sensible shock. has of excess: for by this supposition, which If these experiments prove that the electric is a part of Mr. Franklin's system, the above matter does not pass through the entire thickexperiment is easily accounted for, as follows: ness of the glass, it is a necessary consequence

When I stand on wax, my body is not ca- that it must always come out where it entered. pable of receiving all the electric matter from The next thing I meet with is in the Abthe hook of one phial, which it is ready to bé's fifth letter, where he differs from Mr.

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Franklin, who thinks that the whole power retained by the glass. If after the spark is of giving a shock is in the glass itself, and not drawn from the conductor, you touch the in the non-electrics in contact with it. The coating of the phial (which all this while is experiments which Mr. Franklin gave to prove supposed to hang in the air, free from any this opinion, in his Observations on the Ley, non-electric body) the threads on the conduct

en Bottle,* convinced me that he was in the or will instantly start up, and show that the right; and what the Abbé has asserted, in con- conductor is electrised. It receives this electradiction thereto, has not made me think trisation from the inner surface of the phial, otherwise. The Abbé, perceiving as I sup- which, when the outer surface can receive pose, that the experiments

, as Mr. Franklin what it wants from the hand applied to it, had performed them, must prove his assertion, will give as much as the bodies in contact with alters them without giving any reason for it, it can receive, or if they be large enough, all and makes them in a manner that proves no- that it has of excess. It is diverting to see thing. Why will he have the phial, into how the threads will rise and fall by touching which the water is to be decanted from a the coating and conductor of the phial altercharged phial, held in a man's hand? If the nately. May it not be that the difference bepower of giving a shock is in the water con- tween the charged side of the glass, and the tained in the phial, it should remain there outer or emptied side, being lessened by though decanted into another phial, since no touching the hook or the conductor; the outer non-electric body touched it to take that power side can receive from the hand which touchoff. The phial being placed on wax is no ob- ed it, and by its receiving, the inner side canjection, for it cannot take the power from the not retain so much; and for that reason so water, if it had any, but it is a necessary much as it cannot contain electrises the wameans to try the fact; whereas, that phial's ter, or filings and conductor; for it seems to being charged when held in a man's hand, be a rule, that the one side must be emptied only proves that water will conduct the elec- in the same proportion that the other is filled : tric matter. The Abbé owns, that he had though this from experiment appears eviheard this remarked, but says, why is not a dent, yet it is still a mystery not to be acconductor of electricity an electric subject? counted for. This is not the question ; Mr. Franklin never I am in many places of the Abbé's book sursaid that water was not an electric subject; prised to find that experiments bave succeeded he said, that the power of giving a shock was so differently at Paris, from what they did in the glass, and not in the water; and this, with Mr. Franklin, and as I have always ob his experiments fully prove; so fully, that it served them to do. The Abbé, in making exmay appear impertinent to offer any more; periments to find the difference between the yet as I do not know that the following has two surfaces of a charged glass, will not have been taken notice of by any body before, my the phial placed on wax: for, says he, dont inserting of it in this place may be excused. you know that being placed on a body origiIt is this: hang a phial, prepared for the Ley- nally electric, it quickly loses its virtue ? I den experiment, to the conductor, by its cannot imagine what should have made the hook, and charge it; which done, remove the Abbé think so: it certainly is contradictory communication from the bottom of the phial: to the notions commonly received of electrics now the conductor shows evident signs of be- per se; and by experiment I find it entirely ing electrised; for if a thread be tied round otherwise: for having several times left a

it, and its ends left about two inches long, charged phial, for that purpose, standing on they will extend themselves out like a pair of wax for hours, I found it to retain as much of horns;

but if you touch the conductor, a its charge as another that stood at the same spark will issue from it, and the threads will time on a table. I left one standing on wax fall, nor does the conductor show the least from ten o'clock at night till eight the next sign of being electrised after this is done. I morning, when I found it retain a sufficient think that by this touch, I have taken out all quantity of its charge, to give me a sensible 'the charge of electric matter that was in the commotion in my arms, though the room in conductor, the hook of the phial, and water or which the phial stood had been swept in that filings of iron contained in it; which is no time, which must have raised much dust to more than we see all non-electric bodies will facilitate the discharge of the phial. receive: yet, the glass of the phial retains its I find that a cork-ball suspended between power of giving a shock, as any one will find two bottles, the one fully and the other but that pleases to try. This experiment fully little charged, will not play between them, evinces, that the water in the phial contains but is driven into a situation that makes a no more electric matter than it would do in triangle with the hook of the phials: though an open bason, and has not any of that great the Abbé has asserted the contrary of this, quantity which produces the shock, and is only in order to account for the playing of a cork

ball between the wire thrust into the phial, * See pages 246 to 249, of this volume. and one that rises up from its coating. The

phial which is least charged must have more | empty that the sides of the glass might proelectric matter given to it, in proportion to its tect the flame from the wind. There is no bulk, than the cork ball receives from the hook thing remarkable in all this ; but what follows of the full phial.

is particular. At supper, looking on the The Abbé says,

" That a piece of me- lamp, I remarked, that though the surface of tal leaf hung to a silk thread and electrised, the oil was perfectly tranquil, and duly prewill be repelled by the bottom of a charged served its position and distance with regard phial held by its hook in the air:” this I to the brim of the glass, the water under the find constantly otherwise, it is with me al oil was in great coromotion, rising and falling ways first attracted and then repelled: it is in irregular waves, which continued during necessary, in charging the leaf, to be careful the whole evening. The lamp was kept burnthat it does not fly off to some non-electric ing as a watch light all night, till the oil was body, and so discharge itself when you think spent, and the water only remained. In the it is charged; it is difficult to keep it from morning. I observed, that though the motion flying to your own wrist, or to some part of of the ship continued the same, the water was your body.

now quiet, and its surface as tranquil as that The Abbé says,

That it is not impossi- of the oil had been the evening before. At ble, as Mr. Franklin says it is, to charge a night again, when oil was put upon it, the phial while there is a communication formed water resumed its irregular motions, rising between its coating and its hook.” I have in high waves almost to the surface of the oil, always found it impossible to charge such a but without disturbing the smooth level of phial so as to give a shock: indeed, if it hang that surface. And this was repeated every on the conductor without a communication day during the voyage. from it, you may draw a spark from it as you Since my arrival in America, I have remay from any body that hangs there, but this peated the experiment frequently thos: I is very different from being

charged in such have put a packthread round a tumbler, with a manner as to give a shock. The Abbé, in strings of the same, froin each side meeting order to account for the little quantity of above it in a knot at about a foot distance electric matter that is to be found in the from the top of the tumbler. Then putting phial, says, " that it rather follows the metal in as much water as would fill about one than the glass, and that it is spewed out into third part of the tumbler, I lifted it up by the the air from the coating of the phial." I knot, and swung it to and fro in the air; wonder how it comes not to do so too, when it when the water appeared to keep its place in sifts through the glass, and charges the exte- the tumbler as steadily as if it had been ice. rior surface, according to the Abbé's system ! But pouring gently in upon the water about

The Abbé's objection against Mr. Franklin's as much oil, and then again swinging it in two last experiments, I think, have little the air as before, the tranquillity before posweight in them: he seems, indeed, much at sessed by the water, was transferred to the a loss what to say, wherefore he taxes Mr. surface of the oil, and the water under it was Franklin with having concealed a material agitated with the same commotions as at sea. part of the experiment; a thing too mean for I have shown this experiment to a number any gentleman to be charged with, who has of ingenious persons. Those who are but not shown so great a partiality in relating ex- slightly acquainted with the principles of hyperiments, as the Abbé has done.

drostatics, &c. are apt to fancy immediately that they understand it, and readily attempt

to explain it; but their explanations have To Dr. Pringle, London. been different, and to me not very intelligible. Relating a curious Instance of the Effect of Oil Others, more deeply skilled in those princion Water.

ples, seem to wonder at it, and promise to

consider it. And I think it is worth consider. · PHILADELPHIA, Dec. 1, 1762. DURING our passage to Madeira, the wea- ing; for a new appearance, if it cannot be exther being warm, and the cabin windows con- plained by our old principles, may afford us stantly open, for the benefit of the air, the new ones, of use perhaps in explaining some candles at night flared and run very much, other obscure parts of natural knowledge. which was an inconvenience. At Madeira

B. FRANKLIN. we got oil to burn, and with a common glass tumbler or breaker, slung in wire, and suspended to the ceiling of the cabin, and a little

Dr. Brownrigg to Dr. Franklin. wire hoop for the wick, furnished with corks of the Stilling of Waves by means of Oil.to float on the oil, I made an Italian lamp,

Extracted from sundry letters accompanying. that gave us very good light all over the ta

-Read at the Royal Society, June 2, 1774. ble. The glass at bottom contained water to

ORMATHWAITE, January 27, 1773. about one third of its height; another third By the enclosed from an old friend, a worwas taken up with oil; the rest was left) thy clergyman at Carlisle, whose great learn

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