Description

PRECISION CALIPERS, English, c. early 19th century, signed “Tylor & Pace, London, No. 21.” Made of electrum and steel, with turned steel feet and turned wood handle, the calipers are 7-1/4″ (18 cm) long overall. The rounded jaws open by convenient thumb lever, which drives the geared pointer against a semicircular scale of 0 – 250 units numbered every ten units, each unit being one one-thousandth of an inch. The instrument is in very fine condition, in a mahogany box including some cover slips and specimens for microscope slide preparation. This finely crafted device is possibly designed for measuring thicknesses of microscope slides and cover slips, and is by makers unrecorded in the standard literature (although Clifton lists a Charles Pace, mathematical instrument maker, of London, working c. 1786 – 1805).