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The Richie Photometer cannot be correct since 
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an equal quantity of Light is lost on each side by the reflection which destroys the ratio.
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Same must be the case in Potters Photometer suppose when the two lights through the paper b. b of the
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[[in pencil]] 79
same intensity we interpose a plate of grass between each then the ratio will be disturbed
[Experiment on these points]

Transcription Notes:
Richie Photometer - name checked. 'ss' in glass - appears fs in old hand