Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . a loadstone, is represent-ed in Fig. 97. Innatural magnets thepoles are not usuallyso distinctly markedas in artificial ones,the magnetic forcesbeing more irregularlydistributed. 235. The attrac-tion of a magnetic polefor a piece of ironis not exerted uponthe whole mass, sinceboth a north and asouth pole are neces-sarily developed in theiron. Hence only thatpart of the piece which is nearest the magnet can beattracted, while the remote end must be rep
Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . a loadstone, is represent-ed in Fig. 97. Innatural magnets thepoles are not usuallyso distinctly markedas in artificial ones,the magnetic forcesbeing more irregularlydistributed. 235. The attrac-tion of a magnetic polefor a piece of ironis not exerted uponthe whole mass, sinceboth a north and asouth pole are neces-sarily developed in theiron. Hence only thatpart of the piece which is nearest the magnet can beattracted, while the remote end must be the piece of iron has any considerable length, theend which is repelled will be at such a distance fromthe influence of the magnet, that its repulsion will beoverpowered by the attraction of the extremity whichis near it. If, however, the piece is very short, sothat the repelled pole is brought near to the magnet,the repulsion is proportionally stronger, neutralizingthe attraction to a considerable extent; and, finally,if the iron is of such a form as to bring the two oppo-site poles as near together as possible, so as to expose. 148 DAVISS MANUAL. them nearly equally to the influence of the magnet,the attraction becomes scarcely perceptible. Thus,let M (Fig. 98) be the south pole of a bar or horse- Fig. 98.
Size: 1320px × 1892px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectmagnetism, bookyear18
