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

By Benjamin Franklin

Page 242

a great
part goes away in smoke which you see as it rises, but it affords
you no rays of warmth. One may obtain some notion of the quantity of
fuel thus wasted in smoke, by reflecting on the quantity of soot that
a few weeks firing will lodge against the sides of the chimney, and
yet this is formed only of those particles of the column of smoke
that happen to touch the sides in its ascent. How much more must have
passed off in the air? And we know that this soot is still fuel;
for it will burn and flame as such, and when hard caked together is
indeed very like and almost as solid as the coal it proceeds from.
The destruction of your fuel goes on nearly in the same quantity
whether in smoke or in flame: but there is no comparison in the
difference of heat given. Observe when fresh coals are first put on
your fire, what a body of smoke arises. This smoke is for a long
time too cold to take flame. If you then plunge a burning candle
into it, the candle instead of inflaming the smoke will instantly be
itself extinguished. Smoke must have a certain degree of heat to be
inflammable. As soon as it has acquired that degree, the approach of
a candle will inflame the whole body, and you will be very sensible
of the difference of the heat it gives. A still easier experiment
may be made with the candle itself. Hold your hand near the side of
its flame, and observe the heat it gives; then blow it out, the hand
remaining in the same place, and observe what heat may be given by
the smoke that rises from the still burning snuff. You will find it
very little. And yet that smoke has in it the substance of so much
flame, and will instantly produce it, if you hold another candle
above it so as to kindle it. Now the smoke from the fresh coals laid
on this stove, instead of ascending and leaving the fire while too
cold to burn, being obliged to descend through the burning coals,
receives among them that degree of heat which converts it into flame,
and the heat of that flame is communicated to the air of the room, as
above explained.

4. The flame from the fresh coals laid on in this stove, descending
through the coals already ignited, preserves them long from
consuming, and continues them in the state of red coals as long as
the flame continues that surrounds

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

Page 5
--Account of Domien, an .
Page 39
I did not however go, and it was well I did not; for the next day, the captain missing a silver spoon and some other things which had been taken from the cabin, and knowing these women to be prostitutes, procured a search-warrant, found the stolen goods upon them, and had them punished.
Page 52
They were surprised to see, by this and many other examples, that the _American Aquatic_, as they used to call me, was stronger than those who drank porter.
Page 88
In the choice of these, and in the formation of his plan, Franklin is said to have consulted chiefly with Thomas Hopkinson, Esq; the Rev.
Page 121
A blunt body must be brought within an inch, and draw a spark to produce the same effect.
Page 137
A small upright shaft of wood passes at right angles through a thin round board, of about twelve inches diameter, and turns on a sharp point of iron, fixed in the lower end, while a strong wire in the upper end, passing through a small hole in a thin brass plate, keeps the shaft.
Page 153
12.
Page 163
You may make this figure so acute below, and blunt above, as to need no under plate, it discharging fast enough into the air.
Page 171
I have also smelt the electric fire when drawn through gold, silver, copper, lead, iron, wood, and the human body, and could perceive no difference: the odour is always the same, where the spark does not burn what it strikes; and therefore I imagine it does not take that smell from any quality of the bodies it passes through.
Page 177
This (by the way) shews a new relation between metals and water heretofore unknown.
Page 201
And perhaps the tin tube may lose some of its natural quantity of the electrical fluid, before it receives any from the glass; as that fluid will more readily run off from the ends and edges of it, than enter at the middle: and accordingly, when the glass tube is withdrawn, and the fluid is again equally diffused through the apparatus, it is found to be electrified negatively: for excited glass brought under the balls will increase their repulsion.
Page 224
I am very much pleased that the explication I sent you, of the crooked direction of lightning, meets with your approbation.
Page 247
A strip of tinfoil, three inches long, a quarter of an inch wide at one end, and tapering all the way to a sharp point at the other, fixed between two pieces of glass, and having the electricity of a large glass jar sent through it, will not be discomposed in the broadest part; towards the middle will appear melted in spots; where narrower, it will be quite melted; and about half an inch of it next the point will be reduced to smoke.
Page 250
I am told the same house had formerly been struck by lightning, and much damaged, before these rods were invented.
Page 265
Nairne, mathematical instrument-maker, has made a number of them from mine, and improved them, for his are much more sensible than those I brought from Germany.
Page 278
There is not, in my opinion, any part of.
Page 306
experiment by, i.
Page 323
199.
Page 331
325.
Page 339
218.