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^J.. 19 M 



DeiifUyt Surf, 



JHt'frfififi if ml Foree 

 of Currents 



General Loealiiy 



Chart ustd. : A'^. 6- ft - " ^ 



Ttfifilh lif ifftttl 

 ^pparatiM and, Hi^ itsttf, 



Time tnwlTtjg 



Jirrk (Jf)Uf'r 



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