The needle should be parallel to the coil of A G, and if properly done, the needle will be made to vibrate back and forth slightly at each change in the polarity of I C.
B) Keeping in mind the polarity of the lower end of core E, quickly lower it to the core of H, the circuit being kept closed for a few seconds.
B) Move H M back and forth upon the end of I C, changing its polarity rapidly.
Get clearly in mind the polarity of the coil from the way the current flows through it, then test it with the compass to find whether you are right.
S pole of H M, and again test the polarity of the lower end.
C) Turn the needle end for end in the coil, and see whether its polarity can be reversed.
It results from this arrangement that, under the action of the current, the polarity due to remanent magnetism does nothing but increase.
Under such circumstances, with a somewhat large number of sections, the polarity of the core was nearly constant.
Because, just as it can implant, so it can suddenly change the polarityand turn about the formal energies to any part whatever.
From these experiments it is clear how difficult it is for the property of polarity implanted by the loadstone to be destroyed.
That the polarityof the induced magnet is reversed when it crosses this line may be demonstrated as follows: When it is held beyond (or below) this line (Fig.
When within a short distance consequent points will be formed and the polarity at the ends will be reversed, the bar having four poles, as in the second sketch.
But when contact occurs, the whole of the iron must possess the polarity of that part of the magnet which it touches, namely, negative.
Seeley made the following remarks: The article claims that Mr. Gary has made a discovery of a neutral line or surface, at which the polarity of an induced magnet, while moving in the field of the inducing pole, is changed.
Mr. Gary's claim of a neutral line is of course absurd, but you are wrong in saying that the polarity does not change under the conditions described in the Harper's Monthly article.
My experiment is well illustrated by the writer's diagram, except that the nail should be at the end of the iron wire, where its polarity is of course most strongly marked.
Mr. Gary is perfectly correct in claiming a change of polarity in that experiment, although his other claim of deriving from this change of polarity a continuous motion without consuming energy are manifestly absurd.
In a restricted sense there is a change of polarity over the half of the bar contiguous to the inducing pole; on the other half there is no change of pole in any sense.
In case of an egg yielding a negative (female) polarity “an attempt was made to reverse the sex by painting one end of the egg with a yellow coloring material.
Three eggs tested yielded neutralpolarity and “as predicted the eggs were sterile.
Of five eggs yielding a positive polarity only two hatched, one was a hen and one a rooster, giving an “error in observation.
The polarity of magnetism and electricity also appealed to the senses.
In the case of magnetism, experience soon pushed the mind beyond the bounds of experience, compelling it to conclude that the polarity of the magnet was resident in its molecules.
Going through the entire list of gases and vapours in this way, we find radiation and absorption to be as rigidly associated as positive and negative in electricity, or as north and south polarity in magnetism.
We continue the process of breaking; but, however small the parts, each carries with it, though enfeebled, the polarity of the whole.
The end which last quits the magnet is always opposed in polarity to the end of the magnet with which it, has been last in contact.
Test the polarity of each end of the field with the compass.
What happens to the magnetic polarity of the armature when you turn it slowly by hand and check it with a compass?
Test the polarity of each end of the armature with a compass.
Test the polarity of the armature as you slowly turn it by hand.
Now revolve the arm, and every time the electromagnet or keeper approaches the permanent magnet a current of one polarity will be momentarily developed in the wire of the electromagnet, which is moving.
He discovered that the currents were momentary and occurred at the moment of approach or recession, and that the currents developed by the approach were of opposite polarity to those occurring at the recession.
Another theory of magnetism was that there were two fluids--a boreal and an austral--one developing northpolarity and the other south polarity.
When it is opposite the poles, it has reached the maximum charge and, now, as it passes on it discharges and a current of the opposite polarity is developed in the wire.
Needle of a compass, its polarity reversed by lightning, i.
By electricity we have (here at Philadelphia) frequently given polarity to needles, and reversed it at pleasure.
I forget whether I wrote to you that I have melted brass pins and steel needles, inverted the poles of the magnetic needle, given a magnetism and polarity to needles that had none, and fired dry gunpowder by the electric spark.
As a result of the increased polarity the resistance to rotation is increased, and more power has to be applied to the pulley.
On reaching this last position the rotation would stop if the polarity of the revolving bar were left unchanged, for then the poles facing each other would be of opposite polarity.
The effect of this reversal of the current in one coil after another is to maintain the polarity of the armature practically at the same point, so that the strongest pull is exerted between it and the field magnet poles at all times.
To obtain the polarity of the armature and field it is necessary to pass an electric current through both--that is to say, we must expend electrical energy to obtain power from the machine.
As soon as the current ceases to flow, the polarity of the armature and field dies out, and the rotation of the former comes to an end.
In consequence of the backward rotation a current is generated in the armature coils, and this current, as it traverses the field coils as well as those of the armature, causes the polarity of both parts to increase.
Suppose, however, that we were to reverse the polarity of the rotating part just as it reaches the position of Fig.
If the polarity of the line current were different, the same succession of phenomena would occur, save that the direction of A's rotation would be contrary.
Iron fences invariably exhibit only the polarity by vertical induction; so also small buckets, bells, etc.
Magnetite seems to have acquired its polarity in the same manner, namely by the earth's induction, when the ore contains a large enough percentage of pure iron.
A magnetic field is used with suchpolarity that it blows out the arc.
In compound dynamos it sometimes happens that the machine will excite properly, but that the series coils tend to reverse the polarity of the dynamo, thus reducing the voltage as the load upon the machine increases.
It is well, however, to leave the current on long enough to run the machine up to about half speed and make sure, by means of a voltmeter, that the polarity has been corrected.
Thompson astatic instruments can be provided with polarity indicators, a red disc showing on the scale card where the poles are reversed.
If the faulty coil cannot be repaired quickly, and the machine is urgently required, the coil may be cut out of circuit entirely, or short circuited, and the remaining coils coupled up so as to produce the correct polarity in the pole pieces.
It is essential in making these connections that the polarity be carefully observed.
Method of correcting reversed polarity in large shunt dynamo by transposing the shunt field leads, and then starting up the machine.
What may be said with respect to reversal of polarity of dynamos?
The polarity of the coil is reversed and consequently the direction of the deflection.
When compound or series wound dynamos are running in parallel, their polarity is occasionally reversed while stopping by the current from the machines at work.
The polarity may be reversed without disconnecting or changing the wire.
It is curious to trace the operation of the moral law of polarity in the history of politics, religion, &c.
Thus the current of each brush, in the continuous current machine, is always of the same polarity, and the polarity of one being always positive, and that of the other negative, the current flows continuously in the same direction.
A polarity is maintained throughout: the abstractive and the concretional.
If the polarity is not correct, the switch must be opened again for an instant and closed again; and this process must be repeated until the polarity comes in right.
If the polarityis wrong, the switch must be opened and in a moment thrown in again; and if still wrong, this process must be repeated until the polarity comes right.
The polarity of the generator will vary with the polarity of the field, the direction of rotation, and the connection of the brushes.
It is therefore necessary to have a polarity indicating voltmeter in the circuit and to watch it when starting the machine.
By reversing any one of these we may reverse the polarity of the current delivered.
A test for polarity may be made by placing the ends of wires of opposite polarity in a vessel with water and bringing them within an inch or so of each other.
The polarity of the direct-current terminals depends upon the position the armature happens to be in when the alternating current is applied to it and is very apt to come in wrong when the machine is started.
In Figure 176, when both switches connect to the same polarity the light is out; when one of them is connected to the other pole the light burns.
A difference of polarity exists between any two wires, or points in one wire, where there is any tendency to produce a current.
We assert that the polarity of the first four poles is inconsistent with the polarity of the second four poles.
And a polarity which rouses into action, as we know, at puberty.
But we know so much: we know that it is a dynamic polarity between human beings, and a circuit of force always flowing.
A new, passionate polaritysprings up between men who are bent on the same activity, the polarity between man and woman sinks to passivity.
The moth is drawn to the candle as the draught is drawn to the fire, in the absolute spell of the material polarity of fire.
So that we begin to realize our visible universe as a vast dual polarity between sun and moon.
There is a whole field of consciousness established, with positive polarity of the first plane, negative polarity of the second.
For the true polarity of consciousness in woman is downwards.
The sun sets and has his perfect polarity in the life-circuit established between him and all living individuals.
Which essential waters, at the moon's clue, are only an intense invisible energy, a polarity of the moon.
The individual polaritynow changes, within the individual system.
Having given this general theoretical view, I will now notice particular points relating to the nature of the assumed electric polarity of the insulating dielectric particles.
They refer the effect to magnetism induced in the plate by the magnet; the pole of the latter causing an opposite pole in the nearest part of the plate, and round this a more diffuse polarity of its own kind (120.
The transverse power has a character of polarity impressed upon it.
A]: I purpose that these and many other thoughts which arise respecting specific inductive action and the polarity of the particles of dielectric matter, shall be put to the proof as soon as I can find time.
In the cases of solids and liquids too, bodies may, and most probably do, possess specific differences as to their ability of assuming the polarized state, and also as to the extent to which that polarity must rise before discharge occurs.
At E we have a longitudinal neutrality produced in the same rod when placed magnetic west, the polarity in the latter case being transversal.
I have slightly varied this experiment by heating to redness three similar steel bars, two of which had been previously magnetized to saturation, and placed separately with contrary polarity as regards each other, the third being neutral.
Thus the iron is homogeneous, and its polarity symmetrical.
The power of these wires, if properly prepared, is most remarkable, being able to reverse their polarity under torsion, as if they were completely saturated; and they preserve this power indefinitely if not touched by a magnet.
Thus the rod has passed through all the changes from polarity to neutrality, and from neutrality to polarity, and these changes have taken place with complete symmetry.
The polarityof this is in opposition to the polarity of the thermo-couple which connects into the potentiometer at D and at G.
The thermo-couple is at H, with its polarity as shown by the symbols + and -.
Love and hate, affection and dislike, attachment and aversion, self-esteem and humility have this character of polarity because each pair of sentiments and attitudes represents a different constellation of the same component wishes.
The polarity of the sentiments is, however, one of its evident and striking characteristics.
A similar amount is concerned with refuting various proposals, such as those of Berzelius and Erman, about distributions of magnetic polarityin a conducting wire to account for Oersted's results.
Edward Forbes "On the Manifestation of Polarity in the Distribution of Organised Beings in Time" ("Edinburgh New Phil.
Beaumont's lines of Elevation, or such men as Forbes with his Polarity (41/4.
Forbes, "On the Manifestation ofPolarity in the Distribution of Organised Beings in Time.
In this device the movement of the cam i^2 not only changes the battery but changes the polarity through the magnet M^2, which may be placed anywhere and used for any purpose.
