compounded of this motion
from north to south, or _vice versa_; and of the difference between
its motion from west to east, and that of the equatorial air.
_Observations in Answer to the foregoing, by B. Franklin._
Read at the Royal Society, Nov. 4, 1756.
1st. The supposing a mutual attraction between the particles of water
and air is not introducing a new law of nature; such attractions
taking place in many other known instances.
2dly. Water is specifically 850 times heavier than air. To render a
bubble of water, then, specifically lighter than air, it seems to me
that it must take up more than 850 times the space it did before it
formed the bubble; and within the bubble should be either a vacuum
or air rarefied more than 850 times. If a vacuum, would not the
bubble be immediately crushed by the weight of the atmosphere? And no
heat, we know of, will rarefy air any thing near so much; much less
the common heat of the sun, or that of friction by the dashing on
the surface of the water. Besides, water agitated ever so violently
produces no heat, as has been found by accurate experiments.
3dly. A hollow sphere of lead has a firmness and consistency in it,
that a hollow sphere or bubble of fluid unfrozen water cannot be
supposed to have. The lead may support the pressure of the water it
is immersed in, but the bubble could not support the pressure of the
air, if empty within.
4thly. Was ever a visible bubble seen to rise in air? I have made
many, when a boy, with soap-suds and a tobacco-pipe; but they all
descended when loose from the pipe, though slowly, the air impeding
their motion. They may, indeed, be forced up by a wind from below,
but do not rise of themselves, though filled with warm breath.
5thly. The objection relating to our breathing moist air seems
weighty, and must be farther considered. The air that has been
breathed has, doubtless, acquired an addition of the perspirable
matter which nature intends to free the body from, and which would be
pernicious if retained and returned into the blood; such air then may
become unfit for respiration, as well for that reason, as on account
of its moisture. Yet I should be glad to learn, by some accurate
experiment, whether a draft of air, two or three times inspired,
and expired, perhaps in a bladder, has, or has not, acquired more
moisture than our common air in the dampest weather. As to the
precipitation of water
_At its lower end_, by the agitation of the water, under the whirling part of the circle, between P and S forming Stuart's bush, and by the swelling and rising of the water, in the beginning vacuum, which is, at first, a small, low, broad cone, whose top gradually rises and sharpens, as the force of the whirl encreases.Page 32
I never heard but of one salt rain, and that was where a spout passed pretty near a ship, so I suppose it to be only the drops thrown off from the spout, by the centrifugal force (as the birds were at Hatfield) when they had been carried so high as to be above, or to be too strongly centrifugal for, the pressure of the concurring winds surrounding it: and, indeed, I believe there can be no other kind of salt rain; for it has pleased the goodness of God so to order it, that the particles of air will not attract the particles of salt, though they strongly attract water.Page 48
I make no doubt but that ridges of high mountains do often interrupt, stop, reverberate, or turn the winds that blow against them, according to the different degrees of strength of the winds, and angles of incidence.Page 59
There is nothing remarkable in all this; but what follows is particular.Page 117
_ SIR, You may remember, that when, we were travelling together in Holland, you remarked, that the trackschuyt in one of the stages went slower than usual, and enquired of the boatman, what might be the reason; who answered, that it had been a dry season, and the water in the canal was low.Page 121
The first is to be formed, and to be used in the water on almost the same principles with those of a paper kite used in the air.Page 163
| W.Page 184
Little fuel serves,.Page 197
This passage being made, and, if it runs under any part of the earth, tiled over securely, you may proceed to raise your false back.Page 243
That flame should be a kind of pickle, to preserve burning coals from consuming, may seem a paradox to many, and very unlikely to be true, as it appeared to me the first time I observed the fact.Page 245
in a column through the box C, into the cavities of the bottom plate, like water falling from a funnel, admirable to such as are not acquainted with the nature of the machine, and in itself a pleasing spectacle.Page 255
_) I did not, however, end with squares, but composed also a magic circle, consisting of 8 concentric circles, and 8 radial rows, filled with a series of numbers from 12 to 75 inclusive, so disposed as that the numbers of each circle, or each radial row, being added to the central number 12, they make exactly 360, the number of degrees in a circle; and this circle had, moreover, all the properties of the square of 8.Page 277
| | *Ô» |(sh) Ship, wish.Page 301
These compose what we commonly call _the arts_, which are more or less liberal or mechanical, as they more or less partake of assistance from the operations of the mind.Page 325
loves water and subsists in it, 203.Page 388
seldom heard far from land, 216.