The following article lends support to
Keely's Laws of Attraction and Repulsion:
Law of Attraction
"Juxtaposed coherent aggregates vibrating in unison, or harmonic ratio, are mutually attracted."
Law of Repulsion
"Juxtaposed coherent aggregates vibrating in discord are mutually repelled."
Hydrodynamic Analogies to
Electricity and Magnetism
by George Forbes, Paris, August 15, 1881
Nature
From a scientific and purely theoretical point of view there
is no object in the whole of the Electrical Exhibition at Paris of
greater interest than the remarkable collection of apparatus
exhibited by R. C[arl] A. Bjerknes of Christiana, and
intended to show the fundamental phenomena of electricity and
magnetism by the analgous ones of hydrodynamics. I will try to
give a clear account of these experiements and the apparatus
employed; but no description can convey any idea of the wonderful
beauty of the actual experiments, whilst the mechanism itself is
also of most exquisite construction. Every result which is thus
shown by experiment had been previously predicted by Professor
Bjerknes as the result of his mathematical investigations.
It has long been known that if a tuning fork be struck and
held near to a light object like a balloon it attracts it. This is
an old experiment, and the theory of it has been worked out more
than once. Among others Sir William Thomson gave the theory in the
Philosophical Magazine in 1867. In general words the explanation
is that the air in the neighborhood of the tuning fork is rarefied
by the agitation which it experiences. Consequently the pressure
of the air is greater as the distance from the tuning fork
increases. Thus the pressure on the far side of the balloon is
greater than that on the near side, and the balloon is
attracted.
Dr. Bjerknes has followed out the thory of this action until
he has succeeded in illustrating most of the fundamental phenomena
of electricity and magnetism. He causes vibrations to take place
in a trough of water about six inches deep. He uses a pair of
cylinders fitted with pistons which are moved in and out by a
gearing which regulates the length of stroke and also gives great
rapidity. These cylinders simply act alternately as air
compressors and expanders, and they can be arranged so that both
compress and both expand the air simultaneously, or in such a way
that the one expands while the other compresses the air, and vice
versa. The cylinders are connected by thin india rubber tubing,
and fine metal pipes to the various instruments. A very simple
experiment consists in communicating pulsations to a pair of
tambours, and observing their mutual actions. They consist of a
ring of metal faced on both sides with india rubber and connected
by a tube with the air cylinders. One of them is held in the hand;
the other is mounted in the water in a manner which leaves it free
to move. It is then found that if the pulsations are of the same
kind, i.e., if both expand and both contract simultaneously,
there is attraction.
But if one expands while the other contracts, and vice versa,
there is repulsion. In
fact the phenomenon is the opposite of magnetical and electrical
phenomena, for here like poles attract and unlike poles
repel.
- Law of
Attraction
- "Juxtaposed coherent aggregates
vibrating in unison, or harmonic ratio, are mutually
attracted." Keely
-
- Law of Repulsion
- "Juxtaposed coherent aggregates
vibrating in discord are mutually repelled." Keely
Instead of having the pulsations of a drum we may use the
oscillations of a sphere; and Dr. Bjerknes has mounted a beautiful
piece of apparatus by which the compressions and expansions of air
are used to cause a sphere to oscillate in the water. But in this
case it must be noticed that opposite sides of the sphere are in
opposite phases. In fact the sphere might be expected to act like
a magnet; and so it does. If two oscillating spheres be brought
near each other, then, if they are both moving to and from each
other at the same time, there is attraction; but if one of the
spheres be turned round, so that both spheres move in the same
direction in their oscillations, then there is repulsion. If one
of these spheres be mounted so as to be free to move about a
vertical axis, it is found that when a second oscillating sphere
is brought near to it, the one which is free turns round its axis
and sets itself so that both spheres in their oscillations are
approaching each other or receding simultaneously. Two oscillating
spheres, mounted at the extremities of an arm, with freedom to
move, behave with respect to another oscillating sphere exactly
like a magnet in the neighborhood of another magnetic pole. I
believe that these directive effects are perfectly new, both
theoretically and experimentally. The professor mounts his rod
with a sphere at each end in two ways: (1) so that the
oscillations are along the arm, and (2) so that they are
perpendicular. In all cases they behave as if each sphere was a
little magnet with its axis lying along the direction of
oscillation.
Dr. Bjerknes looks upon the water in his trough as being the
analogue of Faraday's medium; and he looks upon these attractions
and repulsions as being due, not to the action of one body on the
other, but to the mutual action of one body and the water in
contact with it. Viewed in this light, his first experiment is
equivalent to saying that if a vibrating or oscillating body have
its motions in the same direction as the water, the body moves
away from the centre of disturbance, but if in the oppposite
direction, towards it. This idea gives us the analogy of dia- and
para-magnetism. If, in the neighborhood of a vibrating drum, we
have a cork ball, retained under water by a thread, the
oscillations of the cork are greater than those of the water in
contact with it, owing to its small mass, and are consequently
relatively in the same direction. Accordingly we have repulsion,
corresponding to diamagnetism. If, on the other hand, we hang in
the water a ball which is heavier than water, its oscillations are
not so great as that of the water in its vicinity, owing to its
mass, and consequently the oscillations of the ball relatively to
the water are in the opposite direction to those of the water
itself, and there is attraction, corresponding to paramagnetism. A
rod of cork and another of metal are suspended horizontally by
threads in the trough. A vibrating drum is brought near to them;
the cork rod sets itself equatorially, and the metal rod
axially.
If a pellet of iron be floated by a cork on water and two
similar poles (e.g. both north) be brought to its vicinity, one
above and the other below the pellet, the latter cannot remain
exactly in the centre, but will be repelled to a certain distance,
beyond which however there is the usual attraction. The reason is
that when the pellet is nearly in the line joining the two poles
the north pole of the pellet (according to our supposition) is
further from this line than the south one. The angle of action is
less; so that although the north pole is further away, the
horizontal component of the north pole repulsion may be greater
than that of the south pole attraction. Dr. Bjerknes reproduces
this experiment causing two drums to pulsate in concord, the one
above the other. A pellet fixed to a wire, which is attached by
threads to two pieces of cork, is brought between the drums, and
it is found impossible to cause it to remain in the centre.
Dr. Bjerknes conceived further the beautiful idea of tracing
out the conditions of the vibrations of the water when acted on by
pulsating drums. For this purpose he mounted a sphere or cylinder
on a thin spring and fixed as fine paint brush to the top of it.
This is put into the water. The vibrations are in most cases so
small that they could not be detected, but by regulating the
pulsations so as to be isochronous with the vibrations of the
spring, a powerful vibration can be set up. When this is done a
glass plate mounted on four springs is lowered so as to touch the
paint brush, and the direction of a hydrodynamic line of force
depicted. Thus the whole field is explored and different diagrams
are obtained according to the nature of the pulsations. Using two
drums pulsating concordantly, we get a figure of two similar
magnetic poles. If the pulsations are discordant it is like the
figure with two dissimilar poles. Three pulsating drums give a
figure identical with that produced by three magnetic poles. The
professor had previously calculated that the effects ought to be
identical, and I think the same might have been gathered from the
formulae in Sir William Thomson's "Mathematical Theory of
Magnetism," but this only enhances the beauty of the experimental
confirmation.
Physicists have been in the habit of looking upon magnetism as
some kind of molecular rotation. According to the present view it
is a rectilinear motion. Physicists have been accustomed to look
upon the conception of an isolated magnetic pole as an
impossibility, but here, while the oscillating sphere represents a
magnetic molecule with north and south poles, the pulsating drum
represents an isolated pole. These are new conceptions to the
physicist, let us see whither they lead us. The professor shows
that if a rectilinear oscillation constitutes magnetism, a
circular oscillation must signify an electric current, the axis of
oscillation being the direction of the current. According to this
view what would be the action of a ring through which a current is
passing? If the ring were horizontal the inner parts of the ring
would all rise together and all fall together, they would vibrate
and produce the same effect as the rectilinear vibrations of a
magnet. This is the analogue of the Amperian currents.
To Illustrate the condition of the magnetic field in the
neighborhood of the electric currents, Dr. Bjerknes mounted two
wooden cylinders on vertical axis, connecting them by link-work,
which enabled him to vibrate them in the same or opposite ways. To
produce enough friction he was forced to employ syrup in place of
water. The figures which are produced on the glass plate are in
every case the same as those of electric currents, including the
case of currents in parallel and in opposite directions.
The theory is carried out a step further to explain the
attraction and subsequent repulsion after contact of an
electrified and a neutral substance and the passage of a spark.
But it is extremely speculative, and is not as yet experimentally
illustrated, and I think that at present it is better to pass it
by.
I believe that the professor will exhibit his experiments and
give some account of his mathematical investigations, which have
occupied his time for five years, to the Academié des
Sciences this afternoon. His results have not been published
before.
George Forbes, Paris, August 15, 1881
Top of Page |
Master Index |
Home | What's
New | FAQ
| Catalog
