. The velocity and ratio e/m for the primary and secondary [Beta] rays of radium .. . auf-annn exper^nent•vere then abandoned. Proba^.ly irith better pho to. r aphi cEkill in restrainins the darkening effect due to therays I mij^ht have in obtaining a clear imacreof ;he p rays. The radi uni U£ in thi. experinent •.vas loaned ine by Profestjor Rutnerford, and »vas asstrong, if not stronger-, that used by Kauf-:iann in hislast experiments. SECONPARY experimental ar^angement ui^ed to study the-ecrndary radiation is shown diagramatically in fig S.\
. The velocity and ratio e/m for the primary and secondary [Beta] rays of radium .. . auf-annn exper^nent•vere then abandoned. Proba^.ly irith better pho to. r aphi cEkill in restrainins the darkening effect due to therays I mij^ht have in obtaining a clear imacreof ;he p rays. The radi uni U£ in thi. experinent •.vas loaned ine by Profestjor Rutnerford, and »vas asstrong, if not stronger-, that used by Kauf-:iann in hislast experiments. SECONPARY experimental ar^angement ui^ed to study the-ecrndary radiation is shown diagramatically in fig S.\bout 300 ;nilligranmes cf radium bror^.ide of about 30000activity 7/as sealed in u very ti-in glass tube of :;i!ndianetsr and about 5 cts. long. This tube v/as enclosedinside a lead box a, .-/hich had a ilit 5 c^is. long and1 ^:-i wide cut in one side, tnu of the lead box beingof such a thickness that no ,3 rays could pass box ./as ce.^iented to tv/o thick ebonite blocks b and cin such a nan-ner, that one edge of the i^lit coincided D ^ Electroscope,. FigMl. with a face of one of the blocks as indicated in thefigure. ^ d^verrent bean of ^ ---- t-u^, f= fro-nthe vas limited in svidth by the .valis cf blocks. This apparatus v;as placed -O thfcit therays travelled in a horizontal direction. Directly above and puralltl to the ebonite blocksv/as supported a thick screen A ,con str acted of cardboardand filled v/ith -ercury, and iiuving in tne centre a ^/iderectangular opening throuGh ^/nich the radrut^ons couldpass into a gold leaf slectroGCope placed above. Thesubstances whi en were to be stL^died as sources of secon-dary radiation were pi iced beneath this opening in such aposition that the f3 rays fell full upon them. The tnicknercury screen absorbed a large part of tne radiation;and althougn it introduced a snail of secondary radiation, this incretiee was r^ore than offset by the decrease of the rays. The ioniz
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectradioac, bookyear1906
