Benjamin Franklin Experiments With Electricity

Author:      Bigelow, John

Date:        1747

 

 

Benjamin Franklin Experiments With Electricity

 

     It was not only by his demonstration that lightning is identical with

electricity that Franklin did an important work in connection with electrical

science.  He is also entitled to great credit for the stimulus imparted by his

experiments and writings to further discoveries in this field.  Franklin was

by far the most practical among the natural philosophers of his time; and the

development of science in the knowledge and application of electricity has

continued to reflect upon mankind his genius for the useful.

 

     The ancients had no scientific acquaintance with electricity.  The early

Greeks, so far as known, observed but a single phenomenon in connection with

it - the electrification of amber by friction.  Aristotle and Pliny note the

production of electricity by certain fishes, especially the torpedo, a ray

possessing an electrical apparatus with which it kills or stuns its prey and

defends itself against its enemies.  Not before the sixteenth century of the

Christian era was there any recorded scientific study of electrical phenomena.

The early predecessors of Franklin, such as Gilbert, Boyle, and others, are

considered to have created the science of electricity and magnetism.  The

invention of the Leyden jar or vial, in 1745, said to have been "hit upon by

at least three persons working independently," was a very important advance.

 

     The work of Franklin, following so soon upon the then latest step of

progress in Europe, is best made known to the world through his own writings,

particularly in the letters, selected by Bigelow, which appear in the present

account of the philosopher's experiments.

 

     While on a visit to Boston in 1746 Franklin witnessed some electrical

experiments performed by a Mr. Spence, recently arrived from Scotland. Shortly

after his return to Philadelphia the Library Company received from Mr.

Collinson, of London, and a member of the Royal Society, a glass tube, with

instructions for making experiments with it.  With this tube Franklin began a

course of experiments which resulted in discoveries which, humanly speaking,

seem to be exerting a larger material influence upon the industries of the

world than any other discovery of the human intellect.  Dr. Stuber, then a

resident of Philadelphia, and author of the first continuation of Franklin's

Life, who seems to have enjoyed peculiar opportunities of obtaining full and

authentic information upon the subject, gives us the following account of the

observations which this letter brought for the first time to the notice of the

world through Mr. Collinson.

 

     "His observations," says Dr. Stuber, "he communicated, in a series of

letters, to his friend Collinson, the first of which is dated March 28, 1747.

In these he shows the power of points in drawing and throwing off the

electrical matter which had hitherto escaped the notice of electricians.  He

also made the grand discovery of a plus and minus, or of a positive and

negative, state of electricity.  We give him the honor of this without

hesitation; although the English have claimed it for their countryman, Dr.

Watson.  Watson's paper is dated January 21, 1748; Franklin's July 11, 1747,

several months prior.  Shortly after Franklin, from his principles of the plus

and minus state, explained in a satisfactory manner the phenomena of the

Leyden vial, first observed by Mr. Cuneus, or by Professor Muschenbroeck, of

Leyden, which had much perplexed philosophers.  He showed clearly that when

charged the bottle contained no more electricity than before, but that as much

was taken from one side as was thrown on the other; and that to discharge it

nothing was necessary but to produce a communication between the two sides, by

which the equilibrium might be restored, and that then no sign of electricity

would remain.  He afterward demonstrated by experiments that the electricity

did not reside in the coating, as had been supposed, but in the pores of the

glass itself.  After a vial was charged he removed the coating, and found that

upon applying a new coating the shock might still be received.  In the year

1749 he first suggested his idea of explaining the phenomena of thunder-gusts

and of the aurora borealis upon electrical principles.  He points out many

particulars in which lightning and electricity agree, and he adduces many

facts, and reasonings from facts, in support of his positions.

 

     "In the same year he received the astonishingly bold and grand idea of

ascertaining the truth of his doctrine by actually drawing down the lightning,

by means of sharp-pointed iron rods raised into the region of the clouds.

Even in this uncertain state his passion to be useful to mankind displayed

itself in a powerful manner.  Admitting the identity of electricity and

lightning, and knowing the power of points in repelling bodies charged with

electricity, and in conducting their fires silently and imperceptibly, he

suggested the idea of securing houses, ships, etc., from being damaged by

lightning, by erecting pointed rods that should rise some feet above the most

elevated part, and descend some feet into the ground or water.  The effect of

these he concluded would be either to prevent a stroke by repelling the cloud

beyond the striking distance, or by drawing off the electrical fire which it

contained; or, if they could not effect this, they would at least conduct the

electric matter to the earth without any injury to the building.

 

     "It was not till the summer of 1752 that he was enabled to complete his

grand and unparalleled discovery by experiment.  The plan which he had

originally proposed was to erect, on some high tower or other elevated place,

a sentry-box, from which should rise a pointed iron rod, insulated by being

fixed in a cake of resin.  Electrified clouds passing over this would, he

conceived, impart to it a portion of their electricity, which would be

rendered evident to the senses by sparks being emitted when a key, the

knuckle, or other conductor was presented to it.  Philadelphia at this time

afforded no opportunity of trying an experiment of this kind.  While Franklin

was waiting for the erection of a spire, it occurred to him that he might have

more ready access to the region of clouds by means of a common kite.  He

prepared one by fastening two cross sticks to a silken handkerchief, which

would not suffer so much from the rain as paper.  To the upright stick was

affixed an iron point.  The string was, as usual, of hemp, except the lower

end, which was silk.  Where the hempen string terminated, a key was fastened.

With this apparatus, on the appearance of a thunder-gust approaching he went

out into the commons, accompanied by his son, to whom alone he communicated

his intentions, well knowing the ridicule which, too generally for the

interest of science, awaits unsuccessful experiments in philosophy.  He placed

himself under a shed, to avoid the rain; his kite was raised, a thunder-cloud

passed over it, no sign of electricity appeared.  He almost despaired of

success, when suddenly he observed the loose fibres of his string to move

toward an erect position.  He now presented his knuckle to the key and

received a strong spark.  How exquisite must his sensations have been at this

moment!  On this experiment depended the fate of his theory.  If he succeeded,

his name would rank high among those who had improved science; if he failed,

he must inevitably be subjected to the derision of mankind, or, what is worse,

their pity, as a well-meaning man, but a weak, silly projector.  The anxiety

with which he looked for the result of his experiment may be easily conceived.

Doubts and despair had begun to prevail, when the fact was ascertained, in so

clear a manner that even the most incredulous could no longer withhold their

assent.  Repeated sparks were drawn from the key, a vial was charged, a shock

given, and all the experiments made which are usually performed with

electricity.

 

     "About a month before this period some ingenious Frenchman had completed

the discovery in the manner originally proposed by Dr. Franklin.  The letters

which he sent to Mr. Collinson, it is said, were refused a place in the

Transactions of the Royal Society of London.  However this may be, Collinson

published them in a separate volume, under the title of New Experiments and

Observations on Electricity, made at Philadelphia, in America.  They were read

with avidity, and soon translated into different languages.  A very incorrect

French translation fell into the hands of the celebrated Buffon, who,

notwithstanding the disadvantages under which the work labored, was much

pleased with it, and repeated the experiments with success.  He prevailed on

his friend, M. Dalibard, to give his countrymen a more correct translation of

the works of the American electrician.  This contributed much toward spreading

a knowledge of Franklin's principles in France.  The King, Louis XV, hearing

of these experiments, expressed a wish to be a spectator of them. A course of

experiments was given at the seat of the Duc d'Ayen, at St. Germain, by M. de

Lor.  The applause which the King bestowed upon Franklin excited in Buffon,

Dalibard, and De Lor an earnest desire of ascertaining the truth of his theory

of thunder-gusts.  Buffon erected his apparatus on the tower of Montbar, M.

Dalibard at Marly-la-Ville, and De Lor at his house in the Estrapade at Paris,

some of the highest ground in that capital. Dalibard's machine first showed

signs of electricity.  On May 16, 1752, a thunder-cloud passed over it, in the

absence of M. Dalibard, and a number of sparks were drawn from it by Coiffier,

joiner, with whom Dalibard had left directions how to proceed and by M.

Paulet, the prior of Marly-la-Ville.

 

     "An account of this experiment was given to the Royal Academy of

Sciences, by M. Dalibard, in a memoir dated May 13, 1752.  On May 18th, M. de

Lor proved equally as successful with the apparatus erected at his own house.

These philosophers soon excited those of other parts of Europe to repeat the

experiment; among whom none signalized themselves more than Father Beccaria,

of Turin, to whose observations science is much indebted.  Even the cold

regions of Russia were penetrated by the ardor of discovery.  Professor

Richmann bade fair to add much to the stock of knowledge on this subject, when

an unfortunate flash from his conductor put a period to his existence.

 

     "By these experiments Franklin's theory was established in the most

convincing manner.

 

     "Besides these great principles Franklin's letters on electricity contain

a number of facts and hints which have contributed greatly toward reducing

this branch of knowledge to a science.  His friend, Mr. Kinnersley,

communicated to him a discovery of the different kinds of electricity excited

by rubbing glass and sulphur.  This was first observed by M. du Faye, but it

was for many years neglected.  The philosophers were disposed to account for

the phenomena rather from a difference in the quantity of electricity

collected, and even Du Faye himself seems to have at last adopted this

doctrine.  Franklin at first entertained the same idea, but upon repeating the

experiments he perceived that Mr. Kinnersley was right, and that the vitreous

and resinous electricity of Du Faye were nothing more than the positive and

negative states, which he had before observed, and that the glass globe

charged positively, or increased, the quantity of electricity on the prime

conductor, while the globe of sulphur diminished its natural quantity, or

charged negatively.  These experiments and observations opened a new field for

investigation, upon which electricians entered with avidity; and their labors

have added much to the stock of our knowledge.

 

     "Franklin's letters have been translated into most of the European

languages, and into Latin.  In proportion as they have become known, his

principles have been adopted."

 

     In speaking of the first publication of his papers on electricity,

Franklin himself says: "Obliged as we were to Mr. Collinson for the present of

the tube, etc., I thought it right he should be informed of our success in

using it, and wrote him several letters containing accounts of our

experiments.  He got them read in the Royal Society, where they were at first

not thought worth so much notice as to be printed in their Transactions.  One

paper, which I wrote to Mr. Kinnersley, on the sameness of lightning with

electricity, I sent to Mr. Mitchel, an acquaintance of mine, and one of the

members also of that society, who wrote me word that it had been read, but was

laughed at by the connoisseurs.  The papers, however, being shown to Dr.

Fothergill, he thought them of too much value to be stifled, and advised the

printing of them.  Mr. Collinson then gave them to Cave for publication in his

Gentleman's Magazine, but he chose to print them separately in a pamphlet, and

Dr. Fothergill wrote the preface.  Cave, it seemed, judged rightly for his

profession, for by the additions that arrived afterward they swelled to a

quarto volume, which has had five editions and cost him nothing for

copy-money."

 

     The following is an extract from the preface to the first edition of the

pamphlet published by Cave, as above mentioned:

 

     "It may be necessary to acquaint the reader that the following

observations and experiments were not drawn up with the view to their being

made public, but were communicated at different times, and most of them in

letters, written on various topics, as matter only of private amusement.

 

     "But some persons to whom they were read, and who had themselves been

conversant in electrical disquisitions, were of opinion they contained so many

curious and interesting particulars relative to this affair, that it would be

doing a kind of injustice to the public to confine them solely to the limits

of a private acquaintance.

 

     "The editor was therefore prevailed upon to commit such extracts of

letters and other detached pieces as were in his hands to the press, without

waiting for the ingenious author's permission so to do; and this was done with

the less hesitation, as it was apprehended the author's engagements in other

affairs would scarce afford him leisure to give the public his reflections and

experiments on the subject, finished with that care and precision of which the

treatise before us shows he is alike studious and capable."

 

     Dr. Priestley, in his History of Electricity, published in the year 1767,

gives a full account of Franklin's experiments and discoveries.

 

     "Nothing was ever written upon the subject of electricity," he says,

"which was more generally read and admired in all parts of Europe than these

letters.  There is hardly any European language into which they have not been

translated; and, as if this were not sufficient to make them properly known, a

translation of them has lately been made into Latin.  It is not easy to say

whether we are most pleased with the simplicity and perspicuity with which

these letters are written, the modesty with which the author proposes every

hypothesis of his own, or the noble frankness with which he relates his

mistakes, when they were corrected by subsequent experiments.

 

     "Though the English have not been backward in acknowledging the great

merit of this philosopher, he has had the singular good-fortune to be,

perhaps, even more celebrated abroad than at home; so that, to form a just

idea of the great and deserved reputation of Dr. Franklin, we must read the

foreign publications on the subject of electricity, in many of which the terms

'Franklinism,' 'Franklinist,' and the 'Franklinian System' occur in almost

every page.  In consequence of this, Dr. Franklin's principles bid fair to be

handed down to posterity as equally expressive of the true principles of

electricity, as the Newtonian philosophy is of the system of nature in

general."

 

     The observations and theories of Franklin met with high favor in France,

where his experiments were repeated and the results verified to the admiration

of the scientific world.  In the year 1753 his friend Peter Collinson wrote to

him from London: "The King of France strictly commands the Abbe Mazeas to

write a letter in the politest terms to the Royal Society, to return the

King's thanks and compliments, in an express manner, to Mr. Franklin, of

Pennsylvania, for his useful discoveries in electricity, and the application

of pointed rods to prevent the terrible effect of thunder-storms." And the

same Mr. Collinson wrote as follows to the Reverend Jared Eliot, of

Connecticut, in a letter dated London, November 22, 1753: "Our friend Franklin

will be honored on St. Andrew's Day, the 30th instant, the anniversary of the

Royal Society, when the Right Honorable the Earl of Macclesfield will make an

oration on Mr. Franklin's new discoveries in electricity, and, as a reward and

encouragement, will bestow on him a gold medal." This ceremony accordingly

took place, and the medal was conferred.

 

"Philadelphia, 28 Mch., 1747.

 

"To Peter Collinson:

 

     "Sir - Your kind present of an electric tube, with directions for using

it, has put several of us on making electrical experiments in which we have

observed some particular phenomena that we look upon to be new.  I shall

therefore communicate them to you in my next, though possibly they may not be

new to you, as among the numbers daily employed in those experiments on your

side of the water, it is probable some one or other has hit upon the same

observations.  For my own part, I never was before engaged in any study that

so totally engrossed my attention and my time as this has lately done; for

what with making experiments when I can be alone, and repeating them to my

friends and acquaintance, who, from the novelty of the thing, come continually

in crowds to see them, I have, during some months past, had little leisure for

anything else.  I am, etc.,

 

          "B. Franklin."

 

               "Philadelphia, 11 July, 1747.

 

"To Peter Collinson:

 

     "Sir - In my last I informed you that in pursuing our electrical

inquiries we had observed some particular phenomena which we looked upon to be

new, and of which I promised to give you some account, though I apprehended

they might not possibly be new to you, as so many hands are daily employed in

electrical experiments on your side of the water, some or other of which would

probably hit on the same observations.

 

     "The first thing 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 repellency between the cork ball and the shot is likewise destroyed,

1st, by sifting fine sand on it - this does it gradually; 2dly, by breathing

on it; 3dly, by making a smoke about it from burning wood; 4thly, by

candle-light, even though the candle is at a foot distance - these do it

suddenly.  The light of a bright coal from a wood fire, and the light of a

red-hot iron, do it likewise, but not at so great a distance.  Smoke from dry

rosin dropped on hot iron does not destroy the repellency, but is attracted by

both shot and cork ball, forming proportionable atmospheres round them, making

them look beautifully, somewhat like some of the figures in Burnet's or

Whiston's Theory of the Earth.

 

     "N.B. - This experiment should be made in a closet where the air is very

still, or it will be apt to fail.

 

     "The light of the sun thrown strongly upon both cork and shot by a

looking-glass, for a long time together, does not impair the repellency in the

least.  This difference between firelight and sunlight is another thing that

seems new and extraordinary to us.

 

     "We had for some time been of opinion that the electrical fire was not

created by friction, but collected, being really an element diffused among and

attracted by other matter, particularly by water and metals.  We had even

discovered and demonstrated its afflux to the electrical sphere, as well as

its efflux, by means of little, light windmill wheels made of stiff paper

vanes fixed obliquely, and turning freely on fine wire axes; also by little

wheels of the same matter, but formed like water-wheels.  Of the disposition

and application of which wheels, and the various phenomena resulting, I could,

if I had time, fill you a sheet.  The impossibility of electrizing one's self,

though standing on wax, by rubbing the tube, and drawing the fire from it; and

the manner of doing it by passing it near a person or thing standing on the

floor, etc., had also occurred to us some months before.  Mr. Watson's

ingenious Sequel came to hand; and these were some of the new things I

intended to have communicated to you.  But now I need only mention some

particulars not hinted in that piece, with our reasonings thereupon; though

perhaps the latter might well enough be spared.

 

     "1. A person standing on wax and rubbing the tube, and another person on

wax drawing the fire, they will both of them (provided they do not stand so as

to touch one another) appear to be electrized to a person standing on the

floor; that is, he will perceive a spark on approaching each of them with his

knuckle.

 

     "2. But if the persons on wax touch one another during the exciting of

the tube, neither of them will appear to be electrized.

 

     "3. If they touch one another after exciting the tube, and drawing the

fire as aforesaid, there will be a stronger spark between them than was

between either of them and the person on the floor.

 

     "4. After such strong spark neither of them discover any electricity.

 

     "These appearances we attempt to account for thus: We suppose, as

aforesaid, that electrical fire is a common element, of which every one of the

three persons above mentioned has his equal share, before any operation is

begun with the tube.  A, who stands on wax and rubs the tube, collects the

electrical fire from himself into the glass; and, his communication with the

common stock being cut off by the wax, his body is not again immediately

supplied.  B (who stands on wax likewise), passing his knuckle along near the

tube, receives the fire which was collected by the glass from A; and his

communication with the common stock being likewise cut off, he retains the

additional quantity received.  To C, standing on the floor, both appear to be

electrized; for he, having only the middle quantity of electrical fire,

receives a spark upon approaching B, who has an over quantity; but gives one

to A, who has an under quantity.  If A and B approach to touch each other, the

spark is stronger, because the difference between them is greater.  After such

touch there is no spark between either of them and C, because the electrical

fire in all is reduced to the original equality.  If they touch while

electrizing, the equality is never destroyed, the fire only circulating.

Hence have arisen some new terms among us.  We say B (and bodies like

circumstanced) is electrized positively; A, negatively.  Or rather, B is

electrized plus; A, minus.  And we daily in our experiments electrize bodies

plus or minus, as we think proper.  To electrize plus or minus no more needs

to be known than this: that the parts of the tube or sphere that are rubbed

do, in the instant of the friction, attract the electrical fire, and therefore

take it from the thing rubbing; the same parts immediately, as the friction

upon them ceases, are disposed to give the fire they have received to any body

that has less.  Thus you may circulate it as Mr. Watson has shown; you may

also accumulate it or subtract it, upon or from any body, as you connect that

body with the rubber or with the receiver, the communication with the common

stock being cut off.  We think that ingenious gentleman was deceived when he

imagined (in his Sequel) that the electrical fire came down the wire from the

ceiling to the gun-barrel, thence to the sphere, and so electrized the machine

and the man turning the wheel, etc.  We suppose it was driven off, and not

brought on through that wire; and that the machine and man, etc., were

electrized minus - that is, had less electrical fire in them than things in

common.

 

     "As the vessel is just upon sailing, I cannot give you so large an

account of American electricity as I intended; I shall only mention a few

particulars more.  We find granulated lead better to fill the vial with than

water, being easily warmed, and keeping warm and dry in damp air.  We fire

spirits with the wire of the vial.  We light candles, just blown out, by

drawing a spark among the smoke between the wire and snuffers.  We represent

lightning by passing the wire in the dark over a China plate that has gilt

flowers, or applying it to gilt frames of looking-glasses, etc.  We electrize

a person twenty or more times running, with a touch of the finger on the wire,

thus: He stands on wax.  Give him the electrized bottle in his hand. Touch the

wire with your finger and then touch his hand or face; there are sparks every

time.  We increase the force of the electrical kiss vastly, thus: Let A and B

stand on wax, or A on wax and B on the floor; give one of them the electrized

vial in hand; let the other take hold of the wire; there will be a small

spark; but when their lips approach they will be struck and shocked.  The same

if another gentleman and lady, C and D, standing also on wax, and joining

hands with A and B, salute or shake hands.  We suspend by fine silk thread a

counterfeit spider made of a small piece of burnt cork, with legs of linen

thread, and a grain or two of lead stuck in him to give him more weight.  Upon

the table, over which he hangs, we stick a wire upright, as high as the vial

and wire, four or five inches from the spider; then we animate him by setting

the electrical vial at the same distance on the other side of him; he will

immediately fly to the wire of the vial, bend his legs in touching it, then

spring off and fly to the wire of the vial, playing with his legs against

both, in a very entertaining manner, appearing perfectly alive to the persons

unacquainted.  He will continue this motion an hour or more in dry weather.

We electrify, upon wax in the dark, a book that has a double line of gold

round upon the covers, and then apply a knuckle to the gilding; the fire

appears everywhere upon the gold like a flash of lightning; not upon the

leather, nor if you touch the leather instead of the gold.  We rub our tubes

with buckskin and observe always to keep the same side to the tube and never

to sully the tube by handling; thus they work readily and easily without the

least fatigue, especially if kept in tight pasteboard cases lined with

flannel, and sitting close to the tube.  This I mention because the European

papers on electricity frequently speak of rubbing the tubes as a fatiguing

exercise.  Our spheres are fixed on iron axes which pass through them.  At one

end of the axes there is a small handle with which you turn the sphere like a

common grindstone.  This we find very commodious, as the machine takes up but

little room, is portable, and may be enclosed in a tight box when not in use.

It is true the sphere does not turn so swift as when the great wheel is used;

but swiftness we think of little importance, since a few turns will charge the

vial, etc., sufficiently. I am, etc.,

 

          "B. Franklin."

 

(Read before the Royal Society, December 21, 1752)

 

"Philadelphia, 19 October, 1752.

 

"To Peter Collinson:

 

     "Sir - As frequent mention is made in publick papers from Europe of the

success of the Philadelphia Experiment for drawing the electric fire from

clouds by means of pointed rods of iron erected on high buildings, etc., it

may be agreeable to the curious to be informed that the same experiment has

succeeded in Philadelphia, though made in a different and more easy manner,

which is as follows: Make a small cross of two light strips of cedar, the arms

so long as to reach to the four corners of a large thin silk handkerchief when

extended; tie the corners of the handkerchief to the extremities of the cross,

so you have the body of a kite; which, being properly accommodated with a

tail, loop, and string, will rise in the air, like those made of paper; but

this being of silk is fitter to bear the wet and wind of a thunder-gust

without tearing.  To the top of the upright stick of the cross is to be fixed

a very sharp-pointed wire, rising a foot or more above the wood.  To the end

of the twine, next the hand, is to be tied a silk ribbon; and where the silk

and twine join, a key may be fastened.  This kite is to be raised when a

thunder-gust appears to be coming on, and the person who holds the string must

stand within a door or window, or under some cover, so that the silk ribbon

may not be wet; and care must be taken that the twine does not touch the frame

of the door or window.  As soon as any of the thunder-clouds come over the

kite, the pointed wire will draw the electric fire from them, and the kite,

with all the twine, will be electrified, and the loose filaments of the twine

will stand out every way, and he attracted by an approaching finger.  And when

the rain has wetted the kite and twine, so that it can conduct the electric

fire freely, you will find stream out plentifully from the key on the approach

of your knuckle.  At this key the vial may be charged; and from electric fire

thus obtained spirits may be kindled, and all the other electric experiments

be performed which are usually done by the help of a rubbed glass globe or

tube, and thereby the sameness of the electric matter with that of lightning

completely demonstrated.

 

          "B. Franklin."

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