Leaflet with blue spine. The 1881 report from the institute of physics, Basel, by the director, Hagenbach-Bischoff. Bericht der Physicalischen Anstalt im Jahre 1881
Leaflet with blue spine. The 1879 report from the institute of physics, Basel, by the director, Hagenbach-Bischoff. Bericht über die Physicalische Anstalt im Jahre 1879
