Memoirs of Benjamin Franklin; Written by Himself. [Vol. 2 of 2] With his Most Interesting Essays, Letters, and Miscellaneous Writings; Familiar, Moral, Political, Economical, and Philosophical, Selected with Care from All His Published Productions, and Comprising Whatever Is Most Entertaining and Valuable to the General Reader

By Benjamin Franklin

Page 179

end of the iron, made denser there and rarer at the
other. While the iron continues soft and hot, it is only a temporary
magnet; if it cools or grows hard in that situation, it becomes a
permanent one, the magnetic fluid not easily resuming its equilibrium.
Perhaps it may be owing to the permanent magnetism of this globe, which
it had not at first, that its axis is at present kept parallel to
itself, and not liable to the changes it formerly suffered, which
occasioned the rupture of its shell, the submersions and emersions of
its lands, and the confusion of its seasons. The present polar and
equatorial diameters differing from each other near ten leagues, it is
easy to conceive, in case some power should shift the axis gradually,
and place it in the present equator, and make the new equator pass
through the present poles, what a sinking of the waters would happen in
the equatorial regions, and what a rising in the present polar regions;
so that vast tracts would be discovered that now are under water, and
others covered that are now dry, the water rising and sinking in the
different extremes near five leagues. Such an operation as this possibly
occasioned much of Europe, and, among the rest, this mountain of Passy
on which I live, and which is composed of limestone, rock, and
seashells, to be abandoned by the sea, and to change its ancient
climate, which seems to have been a hot one. The globe being now become
a perfect magnet, we are, perhaps, safe from any change of its axis. But
we are still subject to the accidents on the surface, which are
occasioned by a wave in the internal ponderous fluid; and such a wave is
producible by the sudden violent explosion you mention, happening from
the junction of water and fire under the earth, which not only lifts the
incumbent earth that is over the explosion, but, impressing with the
same force the fluid under it, creates a wave that may run a thousand
leagues, lifting, and thereby shaking, successively, all the countries
under which it passes. I know not whether I have expressed myself so
clearly as not to get out of your sight in these reveries. If they
occasion any new inquiries, and produce a better hypothesis, they will
not be quite useless. You see I have given a loose to imagination; but I
approve much more your method of philosophizing, which proceeds upon
actual observation, makes a collection of facts, and concludes no
farther than those facts will warrant. In my

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

Page 3
Touch the wire of the phial repeatedly with your finger, and at every touch you will see the.
Page 6
1, 1747.
Page 8
a wood fire; and the light of red-hot iron do it likewise; but not at so great a distance.
Page 11
Set one of the bottles down on glass, take it up by the hook, and apply its coating to the.
Page 14
13.
Page 15
18.
Page 16
With thin paste or gum-water, fix the border that is cut off on the inside of the glass, pressing it smooth and close; then fill up the vacancy by gilding the glass well with leaf gold or brass.
Page 19
A thin glass bubble, about an inch diameter, weighing only six grains, being half-filled with water, partly gilt on the outside, and furnish'd with a wire hook, gives, when electrified, as great a shock as a man can well bear.
Page 23
Those vapours which have both common and electrical fire in them, are better supported, than those which have only common fire in them.
Page 30
4.
Page 35
Take a pair of large brass scales, of two or more feet beam, the cords of the scales being silk.
Page 40
10 the upper corner.
Page 42
It is this: place the bottle on a glass stand, under the prime conductor; suspend a bullet by a chain from the prime conductor, till it comes within a quarter of an inch right over the wire of the bottle; place your knuckle on the glass stand, at just the same distance from the coating of the bottle, as the bullet is from its wire.
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 45
--Glass, a body extremely elastic (and perhaps its elasticity may be owing in some degree to the subsisting of so great a quantity of this repelling fluid in its pores) must, when rubbed, have its rubbed surface somewhat stretched, or its solid parts drawn a little farther asunder, so that the vacancies in which the electrical fluid resides, become larger, affording room for more of that fluid, which is immediately attracted into it from the cushion or hand rubbing, they being supply'd from the common stock.
Page 46
Thus the particles of electrical fluid belonging to the inside surface go in and out of their pores every stroke given to the tube.
Page 47
You may lessen its whole quantity by drawing out a part, which the whole body will again resume; but of glass you can only lessen the quantity contain'd in one of its surfaces; and not that, but by supplying an equal quantity at the same time to the other surface; so that the whole glass may always have the same quantity in the two surfaces, their two different quantities being added together.
Page 49
And indeed, as that smell so readily leaves the electrical matter, and adheres to the knuckle receiving the sparks, and to other things; I suspect that it never was connected with it, but arises instantaneously from something in the air acted upon by it.
Page 50
But if the fire, with which the inside surface is surcharged, be so much precisely as is wanted by the outside surface, it will pass round through the wire fixed to the wax handle, restore the equilibrium in the glass, and make no alteration in the state of the prime conductor.
Page 53
6d.