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Image
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Source
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Observations
from the source
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Gallenkamp
(1930s)
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Slate resistance, type A
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Gallenkamp
(1930s)
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Slate resistance, type B
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Gallenkamp
(1930s)
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Slate resistance, type C
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Gallenkamp
(1930s)
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Slate resistance, type D
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Gallenkamp
(1930s)
|
Slate resistance, type B with spindle
motion
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Gallenkamp
(1930s)
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Slate resistance, type J
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Gallenkamp
(1930s)
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Slate resistance, type B with middle
point tap
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Gallenkamp
(1930s)
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Cross slate ventilated rheostat
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