. The velocity and ratio e/m for the primary and secondary [Beta] rays of radium .. . APHIC EXPSRIHEMTS. Ejep e r^3 m e_nt_ ^. - The arr iingenent used in this is es- 1sentially the sane as that used by Becquerel and is shown sketched in fig. V, Two netal plates a and c Ts. in len,r;th \vere placed parallel to one anotherin a vertrJcal position 6 m-n apart, and insulated byneans of ebonite. About 2 ens. belo/; the plates wasplaced the radiu?n, ccntainsd in a n-irrow creva?se in ablock of lfid. In the centre of the radium, -ind midv/aybetsreen the plates was fastened a sheet of ^ica c, \v;
. The velocity and ratio e/m for the primary and secondary [Beta] rays of radium .. . APHIC EXPSRIHEMTS. Ejep e r^3 m e_nt_ ^. - The arr iingenent used in this is es- 1sentially the sane as that used by Becquerel and is shown sketched in fig. V, Two netal plates a and c Ts. in len,r;th \vere placed parallel to one anotherin a vertrJcal position 6 m-n apart, and insulated byneans of ebonite. About 2 ens. belo/; the plates wasplaced the radiu?n, ccntainsd in a n-irrow creva?se in ablock of lfid. In the centre of the radium, -ind midv/aybetsreen the plates was fastened a sheet of ^ica c, \v;-!iciextended from the radiuT, up to the pho t o p;r aphi c plate plate v/as v/ranped in a sheet of black paper ,and thenpl^jced a lir^ht tight box containing a thin alumin-ium wnndow throu,q:h v/hich the rays could pass without u c h absorption. The distance between the top of t ii enetal plates and the photofraphic plate fas c-is. When the plates a and b are unchar^ed there ourht tobe obtained on the p-lO togr afthi c plate an cros:;ed 1. 10 c . c i 15 in the centre by a nurruv/ band. On the other hand plates are charged to a potential if the raysare deflected to one side, the pho t c graphi c plate s^ a broad shadow cast by the nica i-creen. In A andB, f:.?:. 6, are shown two photofraphs obtained by thismethod, A taken .vithout an electric filed, ■■ ■ B v/ith apotential differe>Tce between the plates of 3000 volts,corresponding, to a field strength of 6000 volts per appear p^ alike and she?/ no indi-cation of any shadow on the plate. One side in bothphotographs appears darker than the other; this is onaccount of t^ie mica screen not beinj: plviced exactly inthe middle of the radium, thus throwing ncre raTrs toone side than to the other. In C & D are shown twoph(-, +o^raphs taken with the screen pl;ced exactly in thecentre, C bein<^, v/ithout a field and D v/ith one; and bo
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectradioac, bookyear1906
