25

RMS
(a) ------ empty tube induced netage = 0.012v
To vaccum tube volhuster
(b) -------- filed this filmigs,
RMS
induced voltage = 0.011v

(c) ---- coil surrounded by a small copper
of about 0.2mm Hosh
induced netage = 0
Conclusion Nethough the the zie of this filnig in
large the shielding effect is very
small
Bloch: Perhaps the tin filing were over oxidized
that we were working with the oxide rather than tin
metal.
Experiments must be repeated with tin metal.
8/26/49 repeated with metallic tin. No shielding
effect.