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The Blakene Astrolabe

  • Object type

  • Museum number

    1853,1104.1

  • Title (object)

    • The Blakene Astrolabe
  • Description

    This brass astrolabe is the earliest signed and dated European instrument, though its maker Blakene is otherwise unknown.

    The MATER with a double-line decoration on the edge is graduated clockwise 0° to 360°. The inside of the mater is left blank. The purpose of very small punched numerals on the edge ('3, 6, 8, 9, 8'), which differ from the type of numerals otherwise used on the instrument, is unknown.

    The THRONE is tri-lobed, the long shackle and the ring are decorated.

    The RETE contains a large quatrefoil which serves as a base for several star pointers in the ecliptic; its top lobe is inscribed on the rim with the name of the maker and the date. The central disc is hollowed out in four quadrants, the inner ring is attached to the outer ring by a cross-shaped support. The equinoctial bar is counter-changed on each side of the ecliptic. A partial equatorial ring is connected with the tropic of Capricorn by three stylized columns and to the ecliptic by a wavy bar. The thin, flamelike star pointers indicate the following 38 stars: 'Batencaytoz', 'Pantacaytoz', 'Enif', 'Menkar', 'Algon', 'Augethenar', 'Aldebaran', 'Alhayoc', 'Rigil', 'Algeuze', 'Alhabor', 'Algomeyza', 'Egregez', 'Alcuran', 'Equs', 'CorLeonis', 'Alrica', 'Corvus', 'Algorab', 'Deneber', 'Alchimek', 'benenaz', 'Alramek', 'Elfeta', 'Alchi', 'Alhabe', 'Calbalacrab', 'Yed', 'Vega', 'Altair', 'Aldiraz', 'Alrie', 'Libideneb', 'Delfin', 'Alpheraz', 'Menchef', 'Scecor', 'Denebcaytoz'. Each end of the tropic of Capricorn is of dragon head shape; the links between them and the ecliptic are broken. The ecliptic is marked with the usual Latin names of the signs of the zodiac and crudely graduated 12 × 30°. The reverse of the rete bears some markings for a graduation scale on the ecliptic.

    The two PLATES are marked as follows: 1a) laid out and marked for latitude 52° N, with circles for the tropics and the equator, almucantars for every 2°, from both sides (6 to 24 and 6 to 18, 22, 26 respectively) and along the meridian (16 to 36, 40, 44, 48, 52); azimuths for every 15° and lines for the 12 unequal hours numbered 1 to 12; 1b) marked with circles for the tropics and the equator, almucantars for every 2°, azimuths (unlabelled) for every 15° and curves for the 12 unequal hours. The underlying latitude is about 52°. 2a) marked with circles for the tropics and the equator and the lines for the astrological houses in the manner of Regiomontanus, but otherwise blank; 2b) marked with circles for the tropics and the equator, but otherwise blank.

    The BACK is engraved with four altitude scales starting at the top clockwise 90° to 0°, 0° to 90°, 90° to 0°, 0° to 90°:
    A circular zodiacal scale runs anticlockwise starting at the right; it is marked with the usual Latin names of the signs of the zodiac (some abbreviated), and graduated 12 × 30°.
    Further to the inside is a concentric calendrical scale running anticlockwise, starting at the first point of Aries; the equinoxes correspond to March 12.5 and September 15. The scale is marked with the usual Latin names for the months (some abbreviated; 'Mayus' for May).
    In the middle is a concentric calendrical scale consisting of four bands as follows (from the outside): a) 1 to 28 for the solar cycle; b) day letters with indication for leap years 5,6,7 / 2,3,4,5,7 / 1,2,3,4,6,7 / 1,3,4,5,6 / 1,2,3,4,6,7,B / 2,4; c) 7 times 1,2,3,B (for the leap years); d) the Dominical letters for the leap years corresponding to the 'B' in scale 3: E G B D F A C.
    In the lower half is a pair of shadow scales, each divided to 12, labelled every 2.

    The ungraduated, counterchanged ALIDADE, with mihrab-shaped decoration in the centre, has two sighting vanes. The equally ungraduated RULE consists of two tapered arms. The very short, lobe-ended WEDGE is a replacement.

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  • Producer name

  • Date

    • 1342
  • Production place

  • Materials

  • Technique

  • Dimensions

    • Diameter: 218 millimetres
    • Thickness: 7 millimetres
  • Inscriptions

      • Inscription Type

        signature and date
      • Inscription Position

        front, rete, on rim of top lobe of quatrefoil
      • Inscription Language

        Latin
      • Inscription Content

        Blakene me fecit anno do 1342
      • Inscription Transliteration

        Blakene me fecit anno domini 1342
      • Inscription Comment

        signature of maker and date of production
  • Bibliography

    • Ward 1981 326 bibliographic details
    • EPACT 1998 http://www.mhs.ox.ac.uk/epact/catalogue.php?ENumber=67917 bibliographic details
  • Location

    Not on display

  • Exhibition history

    Exhibited:
    2016 Oct – 2017 Feb, Spain, CaixaForum Madrid, Medieval Europe,
    2017 Mar – Jun, Spain, CaixaForum Barcelona, Medieval Europe,
    2017 Jul – Oct, Spain, CaixaForum Zaragoza, Medieval Europe.

    2015 - 2016 11 Dec- 10 Apr, Australia, Brisbane, Queensland Museum, Medieval Europe, power and legacy. 1978 29 Nov-18 Mar, Germany, Cologne, Museum Schnutgen, Die Parler und der Schone Stil (European Art under the Luxembourgers) 1978 15 Jun-15 Oct, Germany, Nuremberg, Bayerisches Nationalmuseum, Kaiser Karl IV: 1316-1378

  • Acquisition name

  • Acquisition date

    1853

  • Department

    Britain, Europe and Prehistory

  • Registration number

    1853,1104.1

Astrolabe; brass; a) rim 0-360 degrees; rete with zodiac circle and equinoctial arc supported by three Gothic pillars; engraved quatrefoil; 38 star-pointers; two plates: I.i) tropics and equinoctial circle; I.ii) tropics ,equinoctial circle and scratched lines of Houses of Heaven; II.i) latitude 52 degrees; II.ii) marked for unspecified latitude; both with almucantars every two degrees, azimuths every fifteen degrees; b) outer edge 0-90-0-90-0; zodiac ring within; calendar-ring within; equinoxes at 12.5 March and 15 September; shadow squares; calendar rings; original alidade; renewed label and wedge.

Astrolabe; brass; a) rim 0-360 degrees; rete with zodiac circle and equinoctial arc supported by three Gothic pillars; engraved quatrefoil; 38 star-pointers; two plates: I.i) tropics and equinoctial circle; I.ii) tropics ,equinoctial circle and scratched lines of Houses of Heaven; II.i) latitude 52 degrees; II.ii) marked for unspecified latitude; both with almucantars every two degrees, azimuths every fifteen degrees; b) outer edge 0-90-0-90-0; zodiac ring within; calendar-ring within; equinoxes at 12.5 March and 15 September; shadow squares; calendar rings; original alidade; renewed label and wedge.

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Object reference number: MCC3706

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