The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 2 [of 3]

By Benjamin Franklin

Page 108

great agitation before, was instantly
calmed upon pouring in only a very small quantity of oil, and that
to so great a distance round the boat as seemed incredible. I have
since had the same accounts from others, but I suspect all of a
little exaggeration. Pliny mentions this property of oil as known
particularly to the divers, who made use of it in his days, in order
to have a more steady light at the bottom.[28] The sailors, I have
been told, have observed something of the same kind in our days, that
the water is always remarkably smoother, in the wake of a ship that
has been newly tallowed, than it is in one that is foul. Mr. Pennant
also mentions an observation of the like nature made by the seal
catchers in Scotland. _Brit. Zool._ Vol. IV. _Article_ Seal. When
these animals are devouring a very oily fish, which they always do
under water, the waves alone are observed to be remarkably smooth,
and by this mark the fishermen know where to look for them. Old Pliny
does not usually meet with all the credit I am inclined to think he
deserves. I shall be glad to have an authentic account of the Keswick
experiment, and if it comes up to the representations that have been
made of it, I shall not much hesitate to believe the old gentleman in
another more wonderful phenomenon he relates of stilling a tempest
only by throwing up a little vinegar into the air.


_Extract of a Letter to Dr. Brownrigg from Dr. Franklin._

_London Nov. 7, 1773._

DEAR SIR,

I thank you for the remarks of your learned friend at Carlisle. I
had, when a youth, read and smiled at Pliny's account of a practice
among the seamen of his time, to still the waves in a storm by
pouring oil into the sea; which he mentions, as well as the use
made of oil by the divers; but the stilling a tempest by throwing
vinegar into the air had escaped me. I think with your friend, that
it has been of late too much the mode to slight the learning of the
ancients. The learned, too, are apt to slight too much the knowledge
of the vulgar. The cooling by evaporation was long an instance of the
latter. This art of smoothing the waves by oil is an instance of both.

Perhaps you may not dislike to have an account of all I have heard,
and learnt, and done in this way. Take it if you please as follows.

In 1757,

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Text Comparison with Experiments and Observations on Electricity Made at Philadelphia in America

Page 1
The non-electric contain'd in the bottle differs when electrised from a non-electric electrised out of the bottle, in this: that the electrical fire of the latter is accumulated _on its surface_, and forms an electrical atmosphere round it of considerable extent: but the.
Page 4
If a cork suspended by a silk thread (_f_) hang between these two wires, it will play incessantly from one to the other, 'till the bottle is no longer electrised; that is, it fetches and carries fire from the top to the bottom of the bottle, 'till the equilibrium is restored.
Page 10
--We find granulated lead better to fill the phial with, than water, being easily warmed, and keeping warm and dry in damp air.
Page 11
S.
Page 15
Upon this, we made what we call'd an _electrical-battery_, consisting of eleven panes of large sash-glass, arm'd with thin leaden plates pasted on each side, placed vertically, and supported at two inches distance on silk cords, with thick hooks of leaden wire, one from each side, standing upright, distant from each other, and convenient communications of wire and chain, from the giving side of one pane, to the receiving side of the other; that so the whole might be charged together, and with the same labour as one single pane; and another contrivance to bring the giving sides, after charging, in contact with one long wire, and the receivers with another, which two long wires would give the force of all the plates of glass at once through the body of any animal forming the circle with them.
Page 16
The excuse for mentioning it here, is, that we tried the experiment differently, drew different consequences from it, (for Mr _Watson_ still seems to think the fire _accumulated on the non-electric_ that is in contact with the glass, page 72) and, as far as we hitherto know, have carried it farther.
Page 17
If now the wire of a bottle electrified in the common way, be brought near the circumference of this wheel, it will attract the nearest thimble, and so put the wheel in motion; that thimble, in passing by, receives a spark, and thereby being electrified is repelled and so driven forwards; while a second being attracted, approaches the wire, receives a spark, and is driven after the first, and so on till the wheel has gone once round, when the thimbles before electrified approaching the wire, instead of being attracted as they were at first, are repelled, and the motion presently ceases.
Page 21
6.
Page 25
Dip both sets in water, and some cohering to each ball they will represent air loaded.
Page 26
of electrical attraction is far beyond the distance of flashing.
Page 28
surface of your body; whereas, if your clothes were dry, it would go thro' the body.
Page 29
ADDITIONAL PAPERS.
Page 31
When part of this natural proportion of electrical fluid, is taken out of a piece of common matter, the triangles formed by the remainder, are supposed to widen by the mutual repulsion of the parts, until they occupy the whole piece.
Page 33
But there is a small portion between I, B, K, that has less of the surface to rest on, and to be attracted by, than the neighbouring portions, while at the same time there is a mutual repulsion between its particles and the particles of those portions, therefore here you can get it with more ease or at a greater distance.
Page 42
In order to this, let it first be considered, _that we cannot, by any means we are yet acquainted with, force the electrical fluid thro' glass_.
Page 43
Its pores are filled with it as full as the mutual repellency of the particles will admit; and what is already in, refuses, or strongly repels, any additional quantity.
Page 44
The quantities of this fluid in each surface being equal, their repelling action on each other is equal; and therefore those of one surface cannot drive out those of the other: but, if a greater quantity is forced into one.
Page 47
36.
Page 52
Price 3s.
Page 53
Smith.