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:
Fotothek df tg Geometrie Vermessung Instrument Winkelmesser. Scan Deutsche Fotothek dftg color MIKCenter Berlin GmbH Seite Basel Geometrische Messinstrumente Halbkreiswinkelinstrument Mastab Lot Papier Kupferstich cm Geometrie Vermessung Instrument Winkelmesser ppn Druck Deutsche Fotothek gefrdert von der Deutschen Forschungsgemeinschaft