Patent drawing - Drawing of Improvements in Magneto-electric Telegraphs Public domain image
Zusammenfassung
Utility Patent Drawings
Public domain photograph of French architecture design drawing, building plan, Paris, France, free to use, no copyright restrictions image - Picryl description
Berühmte Patentzeichnungen aus dem National Archives, Washington DC
Tags
Datum
04/08/1863
Quelle
The U.S. National Archives
Copyright-info
No known copyright restrictions