Hand spectroscope Schmidt & Haensch, Berlin Nickel plated brass direct-vision hand spectroscope (length 9.5 cm) with six revolving lenses and an accessory tube with a lightsource to projext a 400 to 800 nm scale on the prism. In a wooden box (original red velvet lining is missing) Signed "Franz Schmidt & Haensch | 1476", first half 20th century. Collection: private collection