This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Suuri ohikulkukone . en The great transit instrument in the Meridian hall of the Helsinki observatory Made by Utzschneider und Fraunhofer ca fi Suuri ohikulkukone Helsingin observatorion Meridiaanisalissa Utzschneider und Fraunhoferin noin vuonna valmistama own MKFI Collections of the Helsinki Observatory Meridian instruments