| Τίτλος | |
|---|---|
 ,  ,  |
Optical Bench |
 ,  ,  ,  ,  |
Optical discs |
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Optical disk after Hartle |
 ,  ,  ,  ,  |
Orrery |
 ,  ,  ,  |
Oscilloscope |
 ,  ,  ,  |
Ozone generator by Werner Von Siemens |
 |
Pair of bulbs after Violle |
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Pair of candlesticks |
 ,  ,  |
Paper cards with optical illusions |
 |
Papin's digester |