The London, Edinburgh and Dublin philosophical magazine and journal of science . eration or destruction of lines of magnets parallel to theaxis of the cylinder, the motion of lines of poles and so methods are almost identical with those used for planesheets, and it will be sufficient here to call attention to oneor two salient features of the images in cylindrical in the previous articles we shall take A, B to be any twoinverse points inside and outside the cylinder, P and Q twoother inverse points such that OP = e aOA, OQ = £~ aOB,and similar relations will be supposed to
The London, Edinburgh and Dublin philosophical magazine and journal of science . eration or destruction of lines of magnets parallel to theaxis of the cylinder, the motion of lines of poles and so methods are almost identical with those used for planesheets, and it will be sufficient here to call attention to oneor two salient features of the images in cylindrical in the previous articles we shall take A, B to be any twoinverse points inside and outside the cylinder, P and Q twoother inverse points such that OP = e aOA, OQ = £~ aOB,and similar relations will be supposed to hold when the lettersare accented. (i.) If a line of magnets parallel to the axis at AA be gene-rated suddenly, having their positive poles at A and their 388 Dr. G. H. Bryan on Electromagnetic Induction in negative poles at A (fig. 2), the image at time t for inside pointswill be the oppositely magnetized line PP, and for outsidepoints the line QQ having its positive magnetism at Q. Promthe properties of similar triangles and of inversion, PPf is Fig. 2. P A ... ----^ :^i A. parallel and QQis antiparallel to A A, also, since the strengthsof the poles are constant, tlie magnetic moments of the imagesare to one another and to that of the inducing system asPF : QQ : A A, that is as OP : OQ: OA or, in the limitingcase (when Q and Q are infinitely near together), as thedistances OP : OQ : OA. Hence if M be the magnetic moment generated in AA,those of the images PP and QQ/ at time t are — Mem/a andMe-WW/b2, where b = OA. (ii.) Similarly, if a line of magnets of moment M be suddenlygenerated at BB inside the cylinder, the images at time /for outside points will be the oppositely magnetized line QQof magnetic moment — Me- , and for inside points themagnetized line PP having its positive poles at P and ofmagnetic moment Me* /aa2/h2, b being now taken = OB. 7. If a line of poles of strength m suddenly changes positionfrom A to A the effect is equivalent to the superposition of— m
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectscience, bookyear1840
