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The Richie Photometer cannot be correct since [[image - ink drawn]] an equal quantity of Light is lost on each side by the reflection which destroys the ratio. [[image] - ink drawn] Same must be the case in Potters Photometer suppose when the two lights through the paper b. b of the [[end page]] [[start page]] [[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