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 219

the same degree of heat or cold.
The mercury sinks presently three or four degrees, and the quicker if,
during the evaporation, you blow on the ball with bellows; a second
wetting and blowing, when the mercury is down, carries it yet lower. I
think I did not get it lower than five or six degrees from where it
naturally stood, which was at that time sixty. But it is said that a
vessel of water, being placed in another somewhat larger, containing
spirit, in such a manner that the vessel of water is surrounded with the
spirit, and both placed under the receiver of an airpump; on exhausting
the air, the spirit, evaporating, leaves such a degree of cold as to
freeze the water, though the thermometer in the open air stands many
degrees above the freezing point.

I know not how this phenomena is to be accounted for, but it gives me
occasion to mention some loose notions relating to heat and cold, which
I have for some time entertained, but not yet reduced into any form.
Allowing common fire, as well as electrical, to be a fluid capable of
permeating other bodies and seeking an equilibrium, I imagine some
bodies are better fitted by nature to be conductors of that fluid than
others; and that, generally, those which are the best conductors of the
electric fluid are also the best conductors of this; and _e contra_.

Thus a body which is a good conductor of fire readily receives it into
its substance, and conducts it through the whole to all the parts, as
metals and water do; and if two bodies, both good conductors, one
heated, the other in its common state, are brought into contact with
each other, the body which has most fire readily communicates of it to
that which had least, and that which had least readily receives it, till
an equilibrium is produced. Thus, if you take a dollar between your
fingers with one hand, and a piece of wood of the same dimensions with
the other, and bring both at the same time to the flame of a candle, you
will find yourself obliged to drop the dollar before you drop the wood,
because it conducts the heat of the candle sooner to your flesh. Thus,
if a silver teapot had a handle of the same metal, it would conduct the
heat from the water to the hand, and become too hot to be used; we
therefore give to a metal teapot a handle of wood, which is not so good
a conductor as metal. But

Last Page Next Page

Text Comparison with The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 1 [of 3]

Page 11
To be acquainted with the particulars of my parentage and life, many of which are unknown to you, I flatter myself will afford the same pleasure to you as to me.
Page 26
I was tempted to try my hand among them; but, being still a child as it were, I was fearful that my brother might be unwilling to print in his paper any performance of which he should know me to be the author.
Page 75
This affair having turned my thoughts to marriage, I looked around me, and made overtures of alliance in other quarters: but I soon found that the profession of a printer being generally looked upon as a poor trade, I could expect no money with a wife, at least, if I wished her to possess any other charm.
Page 88
Phineas Bond.
Page 93
Peters has taken ten.
Page 120
--Simple and commodious electrical Machine.
Page 125
--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 every where upon the gold like a flash of lightning: not upon the leather, nor, if you touch the leather instead of the gold.
Page 144
The space between any three particles, equally repelling each other, will be an equilateral triangle.
Page 176
_ _Query_, Wherein consists the difference between an _electric_ and a _non-electric_ body? _Answer.
Page 190
This was near the end of the gust.
Page 199
Electrify it, by bringing the excited glass tube near the other end, so as that the balls may stand an inch and an half, or two inches, apart: then, at the approach of the excited tube, they will, by degrees, lose their repelling power, and come into.
Page 228
--Doctrine of Repulsion in electrised Bodies doubted.
Page 269
Page 276
Page 287
_ I must retract the charge of idleness in your studies, when I find you have gone through the doubly difficult task of reading so big a book, on an abstruse subject, and in a foreign language.
Page 291
Page 315
_Electrics per se_ and non-electrics, difference between, i.
Page 320
difference in its qualities, 301.
Page 326
Page 344
'frandfather' replaced by 'grandfather'.