One of the striking exhibitions of magnetism is found in the earth.
Under the conditions above named magnetism is developed in the soft iron bar.
II) and in the chapter on Magnetism the word molecule was frequently used synonymously with atom.
Even electric lighting would be impossible, commercially, if it were not for the part magnetism plays in the production of electricity for this purpose.
Another theory of magnetism was that there were two fluids--a boreal and an austral--one developing north polarity and the other south polarity.
This is the kind of field-magnet universally used for dynamo work, as a much stronger magnetism is developed in this way than it is possible to obtain from any system of permanent steel magnets.
The value of the earth's magnetism is seen most in the science of navigation.
Like electricity, magnetism has had a long history, but little use was made of it till modern times beyond that of the mariner's compass.
If we open the key the current will cease and the magnetism will vanish--that is to say, the molecules will turn back to their neutral position by their own attractions, as has been described in a previous chapter.
The advent of electricity has brought magnetism to the front as one of the great factors in our modern civilization.
A sewing-needle of good steel will retain magnetism for years, and it is almost impossible to knock the magnetism out by hammering it.
The Study of Elementary Electricity andMagnetism by Experiment," Chapters VIII.
Soft iron, which contains less carbon than steel, holds magnetism very poorly; so it is not used for permanent magnets.
By jarring a magnet its molecules are thoroughly shaken up; in fact, most of the magnetism can be knocked out of a weak magnet by hammering it.
Steel retains magnetism for a long time, while soft iron loses it almost instantly.
If the magnetized poker be held level, in an east and west direction, it will no longer be acted upon to advantage by the inductive influence of the earth, and we can easily hammer the magnetism out of it again.
Condensed List of Apparatus FOR "The Study of Elementary Electricity and Magnetismby Experiment.
The power that a piece of steel has to hold magnetism is called retentivity.
For experiments on magnets and magnetism see "Study," Part I.
If a sewing-needle be properly rubbed upon one of the poles of a magnet, it will become strongly magnetized and will retain its magnetism for years.
By this method we can pound magnetismright out of the air with a hammer.
But as all of these are but varied forms of motion, either of a mass as a whole, or molecular, can it be doubted for an instant, that what we call magnetism is but some form of motion?
It will be sufficient here for me to refer to what are called induction coils, which are developments of the principles involved in electro-magnetism and electro-induction.
If a bar of iron that exhibits no evidence of magnetismwhatever be subjected to torsion, it will immediately become a magnet with poles dependent upon the direction of the twist.
Moreover, if a permanent magnet be heated to a red heat, its magnetismis destroyed; for such a heat allows the molecules to freely arrange themselves without any external constraint.
This developed magnetismwill re-act upon a coil of wire, and so move a galvanometer needle.
The magnetism developed in this way was called electro-magnetism, and the iron so wound was called an electro-magnet.
Also, if a permanent magnet be suspended so as to give out a musical sound when it is struck, the magnetism will be much weakened by making it thus to vibrate.
At the focus of this beam a fine cambric needle without magnetism was placed so that the light passed it longitudinally.
This leads to the inquiry as to what magnetism is.
That galvanism and magnetism are but ethereal currents without condensation, induced by peculiar superficial and internal molecular arrangement of the particles of certain substances.
The Aurora Borealis has been generally considered to be in some way connected with the magnetism of the earth, and with the position of the magnetic pole.
Tyndal, it is found that the magnetism of a body is strongest along the line of greatest density.
These have been generally referred to changes of temperature, as in fact, also, the magnetism of the earth is sometimes ascribed to galvanic or electric currents, called forth by a daily change of temperature.
Others have lately attempted to connect the changes of the seasons with the solar spots, as well as with the variations of the magnetism of the earth, but without any marked result.
The contrary deflection of the needle in the northern and southern hemisphere may be formally proclaimed as utterly beyond the reach of the common theory of magnetism to explain.
In applying the theory to the magnetism of the earth, we must bear in mind that the earth is probably magnetic by induction, and not in virtue of its own specific action.
We may, perhaps, here be allowed to allude to another phenomenon connected with terrestrial magnetism and electricity.
It is really a monograph on magnetism written in the thirteenth century.
This was Petrus--we have come to know him as Peregrinus--whose observations on magnetism have excited so much attention in recent years with the republications of his epistle on the subject.
There were a few experiments in electro-magnetism during the succeeding half century.
The larger part of the total number of lines will pass through the iron, as it is a much better conductor of magnetism than air.
The current is gradually reduced in value and the magnetism originally possessed by the watch is removed.
The magnetic field inside the coil is rapidly changing in direction and will tend to destroy any permanent magnetism that may be possessed by an object placed inside of it.
This is in accordance with one of the fundamental laws of magnetism which states that magnetic poles of unlike polarity attract each other and those of like polarity repel each other.
His dress, as usual, was black, with a white cravat, and his manner and bearing had all that magnetism and dignity which so deeply impressed those he met.
From the first he had ardently espoused the cause of the working people, and such was his personal magnetism that he had made hosts of admirers, and had been chosen Deputy with hardly a dissenting voice.
Here he was sent to college, and was soon distinguished by the greatness of his talents, and the rapid progress he made in every species of learning that was put before him.
In 1855 he brought these researches to a conclusion by a general article on magnetic philosophy, having placed the whole subject of magnetism and electromagnetism on an entirely novel and solid basis.
Maxwell's electric and magnetic ideas were gathered together in a great mathematical treatise on electricity and magnetism which was published in 1873.
The study of the relation between the magnet and the circuit conveying an electric current then led Arago to the discovery of the "magnetism of rotation.
The soft lights were just enough for him to see distinctly her small face and shining hair; his own face was in shadow, but she could feel the magnetism of his eyes penetrating through her very being.
There was a remarkable and powerful magnetism in his glance; it was as if a breath of some other world touched her, she seemed to see into possibilities she had never dreamed about.
Electric Anesthesia [445] It is a well known fact that magnetism is used to demagnetize a watch, and that frost is drawn out of a frozen member of the body by the application of snow.
Two types of make-and-break connection are used, the common "buzzer" operated by the magnetism of the core in the coil and the mercury break operated by a small motor.
If the back armature, D, of the magnet is removed the moving armature will work better, as this will prevent the magnetism from acting on both ends of the armature.
The stronger the current, the greater the magnetism of the metal strips, and the farther apart they will be forced, showing a greater defection of the pointer.
She knew he would do so again, and more, and it is hard to be bitter to one who would lay down his life for you, even though he has offended--particularly when he has themagnetism that sweeps you away from your moorings.
She was not sure that she loved him, but his magnetism was overpowering, and her admiration intense.
Discoveries in Electro-magnetism by Ampere and Arago.
Magnetism was equally out of the question, since no conceivable arrangement of magnets could have brought about the movements I had seen.
The bobbin stands for the gun-barrel, the plug for the bullet-car, and the magnetism for the ejecting force.
Moreover, it is conceivable that the car need never touch the sides, for by a proper adjustment of the magnetism of the solenoids we might suspend it in mid-air like Mahomet's coffin, and make it glide along the magnetic axis of the tube.
Small generators sometimes lose their residual magnetism and it is then impossible to start them generating.
A term commonly used to designate the space traversed by the lines of the force of magnetism which is supposed to exist.
She nearly drove my children into frenzy with her malicious animal magnetism business.
Mrs. Eddy has always contended that she herself was so immaculate that malicious animal magnetism could not immediately approach her; but injury to her might be effected through some less pure personality close to her.
There is such magnetism in her little body that when she speaks she almost makes you believe what she believes.
A wave of magnetism passed through the Court, and, to a more or less degree, affected the nerves of every one present.
The first of these was the personal magnetism of Christ, in and through which men came in contact with, and responded to, the attractive forces of those moral and spiritual ideas which Christ set before his followers.
Of the personal magnetism of Christ and the part that it has played in the life of Christendom, I need not now speak.
Sir Thomas Lawrence, the Earl of Northumberland by Sir Joshua Reynolds, and the Earl of Westmorland by Romney.
It was a matter of pride that the Mansion House should never be outdone by the castle in the magnificence of its hospitality.
The main room is a large circular chamber, adorned with statuary, which was built especially for the reception of George IV.
