Microscope Museum

Collection of antique microscopes and other scientific instruments

Carl Zeiss cover glass screw gauge (early 20^th century)

This is a Carl Zeiss cover glass screw gauge or micrometre from the early 20th century. Carl Zeiss produced two types of cover glass gauges: a dial gauge (from about 1889 until 1913) and a screw gauge, like this item, simpler and less expensive, that was sold at least until 1939 (Figure 1). The instrument is signed on the base with ‘Carl Zeiss, Jena’ and 0:1’’ 0,0001’’. The base also contains the serial number 3023. In 1846, Carl Zeiss opened a workshop for precision mechanics and optical instruments in Jena. He focused his activities more and more on microscope production. Soon he was supplying not only the regional market but also shipping his wares around the world. In 1866, Carl Zeiss recruited the physicist Ernst Abbe to help him improve his microscopes. In 1877, Ernst Abbe became a partner in the company. After the passing of Carl Zeiss in 1889, Ernst Abbe created the Carl Zeiss Foundation, which would become the company’s sole owner. Since the 1890s, Abbe’s findings and his style of working have also been adopted in other fields of optics. This led to the creation of all-new products, new business areas and rapid growth for the company. In 1893, the first subsidiary was opened in London. Before the outbreak of WWI, sites were established across the world, which then had to be closed when war broke out. There were more ups and downs between then and 1945. Thereafter, the sites outside Germany have been developing in a stable manner and today, Carl Zeiss AG is a holding company with several subsidiaries. In addition to its sites in Oberkochen and Jena, its main production sites are in Wetzlar and Göttingen in Germany, Dublin and Minneapolis in the US, and Shanghai in China.

Figure 1. Carl Zeiss cover glass screw gauge as pictured in a catalogue from the company from 1934.

References

COVERSLIP MICROMETER, MAKER (SIGNED): CARL ZEISS, JENA (https://www.microscope-antiques.com/zeissmicrometer.html), last accessed on 01/05/2021

HISTORY OF COVER-GLASS (COVERSLIP) MICROMETERS (https://www.microscope-antiques.com/coverglassmicro.html), last accessed on 01/05/2021

ZEISS SCREW COVER-GLASS MICROMETER (https://www.microscope-antiques.com/zeissscrewmicro.html), last accessed on 01/05/2021

LAST EDITED: 01.05.2021