Immisch thermometer with 1″ silvered and hand decorated guilloche dial having dual concentric temperature scales, the outer in black calibrated in degrees Fahrenheit with a range from 30 – 130 and body temperature of 98.4 degrees indicated by a red arrow, the inner marked in red with degrees Celsius having a range from 0 – 50, set on a circular linear register marked “Patent” to the lower part. The centre panel with repeating symmetrical weave pattern signed to the top by the retailer “Pillischer” and “London” to the lower part together with serial no. “2879.” Fine blued steel pointer, low dome bevelled crystal. The miniaturised jewelled movement based on a fluid, probably alcohol, filled Bourdon tube, constructed principally in brass, tensioned on a blued steel hair spring with amplification by levers and gears mounted between two plates.

Very unusual finely executed hand formed silver repoussé decorated case with a central flower and radially extending scroll work, plain bezel, case extension and suspension ring. Together with its original oxblood moroccan leather over timber blue silk and velvet lined presentation case, gilt brass swinging catch and keeper.

Very rare and of great interest, especially to collectors in medical science, this is one of those instruments that is wonderful both outwardly as well as inwardly, the case, movement and dial maker’s skill very evident. The British patent was granted to Karl Moritz Immisch in July 1881 and was generally received with great acclaim. This system, based upon a Bourdon tube applied to temperature measurement, was considered the finest of its mechanical type in its time, received many awards and has stood the test of time. Held in the hand – or more correctly, held to the wrist – it almost immediately responds, showing good sensitivity. It appears to be relatively accurate as well.

Some minor scratches to plain silver surfaces, overall crisp and in working order. The presentation case with minor wear and light abrasions, the fabric interior sound with excellent colour, the border cards worn.

Mechanical thermometers manufactured in the 19th century seem to be really quite rare, predominantly this is so since they were substantially more expensive than the simple mercurial thermometer. There was also some reluctance generally to accept that they could be as accurate.

This Immisch thermometer is a very unusual and delightfully appealing piece of great rarity and undeniable quality, clearly by one of the world’s pre-eminent instrument makers.

Dimensions:  (instrument) 1⅛” diameter x ¼” deep; presentation case 2¼” long x 2″ wide x ¾” deep

Stock No: SI0734

Price: SOLD