Perpetual calendar, brass, unsigned, England, 1790-1860. — view 1 of 1
View 1 of 1 · Image: Science Museum Group · original image source

Instruments · Calendar

Perpetual calendar, brass, unsigned, England, 1790-1860.

DocumentedDocumented from the holding institution's catalogue record.
Maker / attribution
Unrecorded in source
Date
1790-1860
Country of origin
England
Place
England, United Kingdom, England
Object type
Calendar
Dimensions
overall: 3 mm 42 mm, .025kg
Holding institution
Science Museum Group, London
Accession / object no.
1938-377
Credit line
Mr W.E. Miller
Catalogue title (original)
Brass Perpetual Calendar

View the source record ↗

Record summary

Held and catalogued by Science Museum Group, London (object number 1938-377), this is a calendar, made in England, United Kingdom, England, dated 1790-1860. The Atlas places it in the Precision & Scientific Horology period (1750 – 1850) of its Instruments collection. Recorded dimensions: overall: 3 mm 42 mm, .025kg. 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.

Historical context

Precision & Scientific Horology (1750 – 1850)

Harrison solves longitude; Mudge invents the lever; Breguet's Paris workshop defines the modern watch.

The longitude problem was solved by the marine chronometer and lunar distance methods; dividing engines made precision scales possible, and observatories set time by transit instruments.

Read the period in the timelineMore instruments from this periodEarlier: Early Modern Horology

Atlas type guide

Scientific and navigational instruments

Timekeeping has always been tied to astronomy, navigation and measurement. Observatories used transit instruments to determine the exact moment a star crossed the meridian, and set their regulators by it; navigators combined sextant observations with chronometers to find longitude; surveyors, engineers and physicians used counters, pedometers and timers derived from watch and clock technology.

Instruments in this collection show how time measurement supported science and everyday technical life. Their makers were often the same workshops that produced clocks and watches, and their scales and dials document changing units and standards.

What to look for

  • Engraved scales and verniers; the units used (degrees, hours, decimal divisions).
  • Makers' signatures and town names, often on the main plate or limb.
  • Accessories and fitted cases that indicate the intended use.
  • Inventory or institutional marks from observatories, navies or schools.

Dating clues

  • Vernier scales spread after the seventeenth century; dividing engines after Ramsden (1770s) made fine scales common.
  • Mass-produced instruments with patent numbers belong mostly to the nineteenth and twentieth centuries.

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.

Related records