Antique Coverslip Micrometer, Brass Microscope Thickness Gauge, Europe c.1890

A late 19th-century brass coverslip micrometer, constructed with a circular 0–360° enamel dial and lever-operated knife jaws mounted on a four-footed brass base. Measurement is transmitted via a fine chain mechanism to the dial arbor, allowing highly sensitive gauging of very thin material. Instruments of this type were used in microscopy to measure the thickness of glass coverslips in order to adjust objective lens correction. The present example is unsigned, with visible geared transmission beneath the upper plate and original glass-covered dial intact. The brass retains a consistent aged patina with light surface wear appropriate to laboratory use. A precise and technically refined example of late Victorian scientific instrumentation.

Circa: 1880 to 1900

PROVENANCE Thomas Guenther collection.

MEASUREMENTS
Length: 12.86 cm
Width: 5.65 cm
Height: 2.59 cm
Weight: 145 g