Astrolabe Catalogue


Small image of complete astrolabe as rete cannot be removed from mater. Click to enlarge.
Date 1929
Maker W. Watson & Sons
Place London
Material Wood
Inventory no. 21423
Acquisition Presented by W. Watson & Sons in 1929
The rete is of the other (printed) type. The equator is marked on the rete and labeled "EQUATOR". There are a number of stars on this rete that are part of constellations but not named. Only those that are named have been entered in this list.


Type Range & Units Numbered Geometry Location
Ecliptic 0 - 360 Degrees of ecliptic Every 10  Ecliptic ecliptic
Calendar first day of month - last day of month Days of year Every 5  Circular, eccentric ecliptic


There are 25 stars on the rete marked with engraved pointers. Unless otherwise indicated the star name, mediation and declination are as marked/measured on the rete.
Click on the star name or modern star name to search for other astrolabes with the same star.
Star name
(on instrument)
Modern star
(if known)
Mediation Declination Pointer
Caph Caph 8.0° of Aries 60° engraved
β Ceti Deneb Kaitos 10.0° of Aries -19° engraved
Schedir Schedar 11.0° of Aries 42° engraved
α Arietis Hamal 2.0° of Taurus 20° engraved
Aldebaran Aldebaran 10.0° of Gemini 14° engraved
Capella Capella 18.0° of Gemini 44° engraved
Rigel Rigel 19.0° of Gemini -10° engraved
Bellatrix Bellatrix 20.0° of Gemini engraved
Betelgeuse Betelgeuse 28.0° of Gemini engraved
Sirius Sirius 10.0° of Cancer -17° engraved
Procyon Procyon 22.0° of Cancer engraved
Alphard Alphard 10.0° of Leo -9° engraved
Dubhe Dubhe 20.0° of Leo 60° engraved
Merak Merak 14.0° of Virgo 54° engraved
Phagda Phecda 1.0° of Libra 50° engraved
Megrez Megrez 6.0° of Libra 54° engraved
Alioth Alioth 16.0° of Libra 52° engraved
Spica Spica 22.0° of Libra -11° engraved
Mizar Mizar 24.0° of Libra 54° engraved
Benetnasch Benetnasch 24.0° of Libra 46° engraved
Arcturus Arcturus 6.0° of Scorpio 18° engraved
β Librae Zubeneshamali 22.0° of Scorpio -10° engraved
Antares Antares 8.0° of Sagittarius -24° engraved
Vega Vega 8.0° of Capricorn 38° engraved
Altair Altair 25.0° of Capricorn engraved
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