Patent drawing - for A. Bayer's Thermometer Public domain image
Zusammenfassung
Utility Patent Drawings
Public domain photograph of a patent diagram drawings, free to use, no copyright restrictions image - Picryl description
Berühmte Patentzeichnungen aus dem National Archives, Washington DC
Tags
Datum
29/08/1882
Quelle
The U.S. National Archives
Copyright-info
No known copyright restrictions