Victorian Imisch Sharp & Smith Chicago 7130 Patent Fever Thermometer 1800s

Description

Oh so tiny, and oh so rare. How did something this small survive with its original case. I could not get it to work.
This is a late 1800s doctor's clinical or "fever" thermometer, Imisch patent pattern, complete with full hunter type case. The thermometer was used to measure body heat, particularly the existence of abnormally high temperature as a symptom of illness or infection. It worked by contact with the skin and coefficeint expansion of a metal coil inside geared to the calibrated scale. The small size and suspension loop with protective case enabled it to be carried on the doctor's watch chain. Face marked in degrees Fahrenheit, with embossed Makers Mark, Chicago, Patent. A rare survivor of an experimental and not entirely successful innovation. This is a survivor, very scarce.
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