Portable microscope made by Goerz, Berlin-Friedenau, Germany, c. 1928
Dimensions : Weight 61 g
Length : 13,3 cm
This innovative pen/pocket microscope dates to the end of the 1920s: it appears in journal advertisements from 1928 until about 1934. It is made of bakelite (a material invented a decade before) and is stored in a leather pouch. Focusing is achieved by turning the outer knurled tube around the pen.