Dividers, Drawing Instruments, Surveying Instruments and others.
Sold objects are listed here
New objects in Auction by Ricardo - see end of page
Set of 3 Dividers in German Silver and Alu, 19th and 20th Century. 8.5 cm, 13.0 cm, 14.6 cm
Collection of links regarding scientific instruments in the Web: https://www.pinterest.com/geometricum/scientific-instruments-in-the-web/