Clockwork timer used by renal dialysis patients to time blood clotting reaction when adding heparin to blood for dialysis

Record summary

Held and catalogued by Science Museum Group, London (object number 1994-509), this is a timer by English Clock Systems Ltd., A Branch of Smith and Sons (England) (maker), dated 1940-1980. The Atlas places it in the Modern Mechanical Horology period (1945 – 1969) of its Instruments collection. The record is illustrated with 1 photograph.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

The source record does not include a narrative description. The structured fields above are reproduced from it.

Atlas type guide

Timers, stopwatches, chronoscopes and time recorders

Instruments for measuring short intervals or recording when something happened form a large and practical branch of horology. Sports stopwatches and split-seconds timers, laboratory chronoscopes (such as Hipp's, which measured thousandths of a second for psychology and ballistics experiments), metronomes for music, watchmen's clocks that recorded patrol rounds, and the time recorders that clocked factory workers in and out all derive from clock and watch technology.

These objects matter historically because they show timekeeping leaving the observatory and the drawing room and entering industry, science and sport. Many were mass-produced, and their dials, scales and patents chart the rise of electrification and industrial management.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

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