Franklin Describes His Experiments

Today’s installment concludes Benjamin Franklin Experiments With Electricity,
the name of our selection from The Complete Works of Benjamin Franklin; Including His Private as Well as His Official and Scientific Correspondence, and Numerous Letters and Documents Now for the First Time Printed, With Many Others not Included in any Former Collection, Also, the Unmutilated and Correct Version of His Autobiography by John Bigelow (edited) and by Benjamin Franklin published in 1887.  For works benefiting from the latest research see the “More information” section at the bottom of these pages.

The selection is serialized in five installments for daily reading.

Previously in Benjamin Franklin Experiments With Electricity.

Time: 1747 and 1752
Place: Philadelphia

“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 public 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 be 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 it 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.”

This ends our series of passages on Benjamin Franklin Experiments With Electricity edited by John Bigelow and Benjamin Franklin from their book The Complete Works of Benjamin Franklin; Including His Private as Well as His Official and Scientific Correspondence, and Numerous Letters and Documents Now for the First Time Printed, With Many Others not Included in any Former Collection, Also, the Unmutilated and Correct Version of His Autobiography published in 1887. This blog features short and lengthy pieces on all aspects of our shared past. Here are selections from the great historians who may be forgotten (and whose work have fallen into public domain) as well as links to the most up-to-date developments in the field of history and of course, original material from yours truly, Jack Le Moine. – A little bit of everything historical is here.

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