Keywords: NJFjord.png en Niels Johannes Fjord 1825-1891 Danish physicist Salmonsens konversationsleksikon bind XIII Author 1919 This image was first published in the 2nd 1915 “1930 edition of Salmonsens konversationsleksikon The copyrights for that book have expired and this image is in the public domain PD-old Niels Johannes Fjord |