South magnetic pole

“ At the magnetic equator there is no dip at all, because the needle being equally distant from the north and south magnetic poles, remains horizontal. As you travel north the needle dips more and more until it reaches the region of the north magnetic pole when it is almost perpendicular—pointing straight down. ”

“ We must expect a considerably greater displacement of the position of the southern pole. At Hobart Town, which is the nearest station to this pole, calculation gives too low a dip by 3° 38′, as far as the observation can be depended upon. It seems probable, therefore, that the actual south magnetic pole is considerably to the north of the position given by our calculation ”

“ Terrestrial Magnetism Consider the Earth as a huge magnet surrounded by lines of magnetic flux connecting its two magnetic poles. These magnetic poles are near, but not coincidental with, the Earth’s geographic poles. Since the north seeking end of a compass needle is conventionally called the north pole, or positive pole, it must therefore be attracted to a south pole, or negative pole. ”

“ Her influence on terrestrial magnetism is now ascertained; the magnetism of the hemisphere that is turned toward the earth attracts the pole of our needles that is turned toward the south and increases the magnetism of our hemisphere; and as the magnetic, like the gravitating force, extends through space, the induction of the sun, moon and planets must occasion perpetual variations in the intensity of terrestrial magnetism, by the continual changes in their relative positions. ”

“ If we look away from the actual condition of the earth and take the question in its generality, there may certainly exist more than two magnetic poles; but it does not appear to have been noticed that if, for example, two north poles exist, there must necessarily be between them yet a third point, which is likewise a magnetic pole, but is properly neither a north nor a south pole, or is both if that expression be preferred. ”

“ On these rocks, we have found orientation changes; that’s why we know the magnetic field have been upside-down and passed through constant changes.
The magnetic north pole changes its exact position in time. Currently, it is nearby Canada and is moving to the Siberian land, located in Russia. Over the last 30 years, the geographic position of the magnetic pole north has changed more than in the previous 90 years. ”

“ Well, Benjy, the famous Arctic discoverer, Sir James Ross, in 1832, discovered that the northern magnetic pole was situated in the island of Boothia Felix, in latitude 70 degrees 5 seconds and longitude 96 degrees 46 seconds West. It was discovered by means of an instrument called the dipping needle, which is just a magnetised needle made for dipping perpendicularly instead of going round horizontally like the mariner’s compass. A graduated arc is fitted to it so that the amount of dip at any place on the earth’s surface can be ascertained. ”

“ Unless the path of the induction is entirely inside the metal, free magnetic poles are developed at those parts of the metal where induction enters and leaves, the polarity being south at the entry and north at the exit of the flux. These free poles produce a magnetic field which is superposed upon that arising from other sources. The resultant magnetic field, therefore, is compounded of two fields, the one being due to the poles, and the other to the external causes which would be operative in the absence of the magnetized metal. ”

“ The difficulty was overcome by C. A. Coulomb, who by using very long and thin magnets, so arranged that the action of their distant poles was negligible, succeeded in establishing the law, which has since been confirmed by more accurate methods, that the force of attraction or repulsion exerted between two magnetic poles varies inversely as the square of the distance between them. Since the poles of different magnets differ in strength, it is important to agree upon a definite unit or standard of reference in terms of which the strength of a pole may be numerically specified. ”

“ The Æthiopian magnets if they be powerful, like those brought from China, because all strong ones show the effect more quickly and more plainly, attract more strongly in the parts nearest the pole, and turn about until pole looks directly at pole. The pole of a stone more persistently attracts and more rapidly seizes the corresponding part (which they term the adverse part) of another stone; for instance, North pulls South; just so it also summons iron with more vehemence, and the iron cleaves to it more firmly whether it have been previously excited by the magnet, or is untouched. ”

“ Further observations in circles round about the approximate point of each magnetic pole would add very much to our knowledge of terrestrial magnetism.
Terrestrial magnetism is altogether a most intricate and difficult science, but it is perfectly obvious that one very great use of an intimate study of this subject is for purposes of navigation. In the days of sailing ships, the finest course that was laid till recent years was to a quarter of a point or nearly three degrees of the circle, nowadays no steamer of any importance steers a wider course than one degree. ”

“ Not only has the north magnetic pole gradually been changing its position, as shown by the records of three centuries, but, according to Barlow, every place has a magnetic pole and equator of its own; and according to Faraday the earth is a great magnet, whose power, as estimated by Gauss, is equal to that which would be conferred if every cubic yard of it contained six one-pound magnets ”

“ This last method of arrangement is called by Ewing the “one-pole” method, because the magnetometer deflection is mainly caused by the upper pole of the rod (Magnetic Induction, p. 40) . For experiments with long thin rods or wires it has an advantage over the other arrangements in that the position of the poles need not be known with great accuracy, a small upward or downward displacement having little effect upon the magnetometer deflection. ”

“ A terrella sends out in an orbe its powers in proportion to its vigour and quality. But when iron or any other magnetick of convenient magnitude comes within its orbe of virtue, it is allured; but the nearer it comes to the body, the more quickly it runs up to it. They move towards the magnet, not as * to a centre, nor towards its centre. For they only do this in the case of the poles themselves, when namely that which is being allured, and the pole of the loadstone, and its centre, are in the same straight line. ”

“ It has poles, not mathematical points, but natural termini of force excelling in primary efficiency by the co-operation of the whole: and there are poles in like manner in the earth which our forefathers sought ever in the sky: it has an æquator, a natural dividing line between the two poles, just as the earth has: for of all lines drawn by the mathematicians on the terrestrial globe, the æquator is the natural boundary, and is not, as will hereafter appear, merely a mathematical circle. It, like the earth, acquires Direction and stability toward North and South, as the earth does ”

“ The north pole of the weak magnet points in the same direction as those of the strong ones, but since it is in contact with the south pole of a stronger magnet, there is an excess of south magnetism in the neighbourhood of its north pole, which causes the small magnet to appear oppositely magnetized. ”