Collection online

astrolabe

  • Object type

  • Museum number

    1888,1201.279

  • Description

    The MATER of this gilt brass astrolabe is unusually shallow, only accommodating one plate. The rim bears two equal 24-hour scales, one in Arabic numerals twice from 1 to 12 and the other in Roman numerals from I to XXIV. Both scales are divided to half hours. Further to the centre is an altitude scale numbered four times 0° to 90° starting at the east-west line, divided to 5° and subdivided to single degrees. The rim is riveted to the back plate. The inside of the rim has a recess at 12 o'clock underneath the throne to accommodate the tongue of the plate. The inside of the mater is devoid of markings.

    The THRONE consists of a circular disc with a swivelling plate fitted over it.

    The RETE has a foliate scroll design outside the ecliptic; the solstitial bar inside the ecliptic above the equinoctial bar is broken into a heart shape. The star pointers are flame-shaped, the names of 39 stars are given with their magnitudes, some additionally with their Arabic names.
    The ecliptic is marked with the usual Latin names of the zodiacal signs, numbered 1 to 12. Each sign is divided to 30°, numbered by 10°, divided to 2°.

    The PLATE is marked on both sides with circles for the equator (and 'AEQUATOR [Aries] [Libra] on 1a and 'AEQUINOCTIALIS' on 1b) and the tropics ([Cancer] on 1a and 'TROPIC<US> CANCRI' on 1b and 'TROPIC<US> CAPRICORNI'), azimuths for every 10° (numbered by 10), almucantars for every 2° (numbered by 2), the lines for the unequal hours (numbered 1 to 12), the lines for the astrological houses in the manner of Regiomontanus (numbered I to XII), the 'HORIZON OBLIQUS' and the twilight curve ('CREPVSCVLINA SIVE AVRORA'). The cardinal directions are marked ‘SEP{TENRIO}, OR{IENS}, ME{RIDIES}, OC{CIDENS}'.
    The two sides are marked and laid out for the following latitudes: 1a) 'LA{TITUDO} 45; 1b) 'AD ELE{VATIO} POLI' 48.

    The BACK of the instrument has several concentric scales as follows (from the outside):
    1) An altitude scale, marked four times 0° to 90° starting on the east-west line, numbered by 10°, divided to 5° and subdivided to single degrees.
    2) A scale with the usual Latin names of the zodiacal signs and the corresponding symbols, each sign divided to 30°, marked by 10°, divided to 5°, with subdivisions to single degrees;
    3) A Julian calendar scale with the usual Latin names of the months, divided to the corresponding number of days, every tenth day marked with divisions to five days and subdivisions to single days. The equinoxes correspond with March 10½ and September 13½;
    4) A Gregorian calendar scale with the usual Latin names of the months, divided to the corresponding number of days, every tenth day marked with divisions to five days and subdivisions to single days.

    The bottom half of the vacant space inside these circles is taken up by a double SHADOW SCALE marked 'VMBRA VERSA' and 'VMBRA RECTA' to the bases 12 and 60 respectively, numbered by 3 and 10 digits respectively; the scale to the base of 60 is further divided to 5 digits and subdivided to single digits.

    The top half contains two HORARY QUADRANTS laid out for equal and unequal hours for the same latitudes as the plates: on the left for latitude 45°, and on the right for latitude 48°.

    Neither the RULE nor the ALIDADE has any markings; the alidade has a pair of pinnules on each sight.

    More 

  • Producer name

  • Date

    • 1583 (circa)
  • Production place

  • Materials

  • Dimensions

    • Diameter: 170 millimetres
    • Thickness: 3 millimetres
  • Curator's comments

    This instrument is neither signed nor dated, but the close resemblance to an astrolabe attributed to Johann Anton Linden of Heilbronn in Germany in the Museum of the History of Science in Oxford (Inventory no. 48380; EPACT 1998, http://www.mhs.ox.ac.uk/epact/catalogue.php?ENumber=28988) suggests this date and maker.
    Besides the usual features of an astrolabe this instrument has on the back two different horary quadrants made for the same latitudes as the plates.
    [S. Ackermann, EPACT 1998, http://www.mhs.ox.ac.uk/epact/catalogue.php?ENumber=95950]

    More 

  • Bibliography

    • Ward 1981 342 bibliographic details
    • EPACT 1998 http://www.mhs.ox.ac.uk/epact/catalogue.php?ENumber=95950 bibliographic details
  • Location

    Not on display

  • Acquisition name

  • Acquisition date

    1888

  • Department

    Britain, Europe and Prehistory

  • Registration number

    1888,1201.279

Astrolabe; brass; a) outer ring rim 1-12,1-12; I-XXIII; ring 0-90-0-90-0; rete with 36 star-pointers and equatorial ring; one plate: 48 and 45 degrees; almucantars and azimuths every ten degrees; crepuscular line; lines for unequal hours of night and for Houses of Heaven; b) outer ring 0-90-0-90-0; ring with zodiac signs and degrees; Julian calendar; equinoxes at 10.5 March and 13.5 September; Gregorian calendar, equinoxes at azimuths every 10 degrees; twilight line and umbra recta and umbra versa; lines for unequal and equal hours; alidade with pair of pinnules in each sight.

Astrolabe; brass; a) outer ring rim 1-12,1-12; I-XXIII; ring 0-90-0-90-0; rete with 36 star-pointers and equatorial ring; one plate: 48 and 45 degrees; almucantars and azimuths every ten degrees; crepuscular line; lines for unequal hours of night and for Houses of Heaven; b) outer ring 0-90-0-90-0; ring with zodiac signs and degrees; Julian calendar; equinoxes at 10.5 March and 13.5 September; Gregorian calendar, equinoxes at azimuths every 10 degrees; twilight line and umbra recta and umbra versa; lines for unequal and equal hours; alidade with pair of pinnules in each sight.

Image description

Recommend


Feedback

If you’ve noticed a mistake or have any further information about this object, please email: collectiondatabase@britishmuseum.org 

View open data for this object with SPARQL endpoint

Object reference number: MCC3798

British Museum collection data is also available in the W3C open data standard, RDF, allowing it to join and relate to a growing body of linked data published by organisations around the world.

View this object

Support the Museum:
donate online

The Museum makes its collection database available to be used by scholars around the world. Donations will help support curatorial, documentation and digitisation projects.

About the database

The British Museum collection database is a work in progress. New records, updates and images are added every week.

More about the database 

Supporters

Work on this database is supported by a range of sponsors, donors and volunteers.

More about supporters and how you
can help  

Loading...