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Keywords from Image Description:
Polemoskop Hevelius. en Technical drawing of periscope with lenses by Johannes Hevelius published in his book Selenographia sive lunae descriptio Hevelius called his Invention polemoscope de Technische Zeichnung eines Periskops mit Linsen von Johannes Hevelius verffentlicht in seinem Werk Selenographia sive lunae descriptio Hevelius