Armillary / astronomical instrument by Butterfield, Michael, France, 1685-1724 — view 1 of 4
View 1 of 4 · Image: Science Museum Group · original image source

Instruments · Quadrant - optical

Armillary / astronomical instrument by Butterfield, Michael, France, 1685-1724

DocumentedDocumented from the holding institution's catalogue record.
Maker / attribution
Butterfield, Michael (maker); Michael Butterfield (maker)
Date
1685-1724
Country of origin
France
Place
Paris, France, Paris; France
Object type
Quadrant - optical
Dimensions
Overall: 1700 mm x 1100 mm x 780 mm, 42 kg
Holding institution
Science Museum Group, London
Accession / object no.
1876-1530
Credit line
Meteorological Office
Catalogue title (original)
Astronomical quadrant with stand, 1685-1724

View the source record ↗

Record summary

Held and catalogued by Science Museum Group, London (object number 1876-1530), this is a quadrant - optical by Butterfield, Michael, made in Paris, France, Paris; France, dated 1685-1724. The Atlas places it in the Early Modern Horology period (1600 – 1750) of its Instruments collection. Recorded dimensions: Overall: 1700 mm x 1100 mm x 780 mm, 42 kg. The record is illustrated with 4 photographs.

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

Science Museum Group description

Dated to the early eighteenth century, this astronomical quadrant was made by the French instrument maker Michael Butterfield in Paris. Unlike later instruments the sighting telescope is fixed to the quadrant that pivots at the centre of its graduated radial scale that is marked in degrees. The astronomical quadrant was employed to measure the angle of a celestial object from the zenith. Operated in conjunction with a transit instrument it could be used to check the running rate of astronomical clocks known as regulators. The instrument's orientation in both the horizontal and vertical could finely adjusted using both the plumb bob and spirit level.

Historical context

Early Modern Horology (1600 – 1750)

Huygens' pendulum and balance spring transform accuracy; English makers develop the anchor and deadbeat escapements.

Pocket sundials, Butterfield dials and sandglasses remained essential companions to imperfect clocks; navigators used sandglasses and the log line; observatories began to combine telescopes with pendulum clocks.

Read the period in the timelineMore instruments from this periodEarlier: Renaissance Horology

Atlas type guide

Astrolabes, quadrants and astronomical compendia

The planispheric astrolabe is a two-dimensional model of the sky. A pierced rotating star map (the rete) turns over a plate engraved for a particular latitude; by aligning a star or the sun with its observed altitude, the user can read the time of day or night, the time of sunrise and sunset, and solve many other astronomical problems. Developed in the Hellenistic world and refined by astronomers in the Islamic world from the eighth century, it reached Latin Europe through al-Andalus.

Quadrants, compendia, armillary spheres and later orreries belong to the same family of instruments that model the heavens. They were teaching tools, status objects and practical time-finders. Many surviving examples are signed and dated, which makes them important evidence for the history of instrument-making workshops in Baghdad, Isfahan, Lahore, Toledo, Louvain, Nuremberg, London and elsewhere.

What to look for

  • The latitudes engraved on the plates — they show which cities the instrument was made for.
  • The script and calendar used: Arabic or Persian inscriptions, abjad numerals, Hebrew or Latin text indicate tradition and region.
  • The design of the rete: the number of named stars and the style of the star pointers changes by region and period.
  • Shadow squares, unequal-hour lines and zodiac scales on the back (dorsum).
  • Signatures, dedications and dates, often hidden on the throne (kursi) or the back.

Dating clues

  • Signed and dated astrolabes allow precise dating; undated ones are attributed by star positions on the rete, which shift slowly through precession.
  • Gothic-style retes with tracery are typical of European instruments of the fourteenth and fifteenth centuries.
  • Printed paper astrolabes and planispheres became common from the sixteenth century onward.

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