Clockmaker Emil Oskar Richter (1841-1907) founded 'E.O. Richter & Co' in Chemnitz, Saxony in 1877. A company that manufactured high-quality drawing instruments. The patent for this tool ran from 1892 to 1905, but of course it has been manufactured longer. This version is from ca. 1910. Operation: This brushed steel instrument has an arm with a chromed pin that moves up and down by interacting with one of the three interchangeable brass sprockets (various dashed-line types). Pulled along a conductor (e.g. a ruler) a line consisting of dots or dashes at exactly the same distance is drawn. The instrument must have been a pleasure to own and to use! The wooden, with black imitation leather covered cassette has a sliding lock and carries the logo of the company. The inside is lined with purple velvet. The condition of the complete set is good, but considering its age only some wear as a result of handling and age Dimension (cassette): 8.9 cm x 7.6 cm Markings: Logo 'E.O. Richter ' on cassette lid and on all parts of the instrument. Details: On the lid of the cassette, there is a transfer stamp of the Technical Bookstore J. Waltman Jr.-Delft (since 1863 to the present day specialised in technical and scientific literature) Shipping: fast, carefully packed, track & trace and registered.