Astrolabe Catalogue


Small image of astrolabe rete separated from astrolabe. Click to enlarge.
Date 1559
Maker Thomas Gemini
Place London
Material Brass
Inventory no. 42223
Acquisition Transferred from the University Observatory, Oxford, in 1936
The rete is of the arsenius type. This rete has true three-dimensionality in the strapwork (more usually retes of this school merely give the impression of interlacing by means of engraved shading).The zodiac on the rete is labelled: Aries , Taurus , Gemini , [only the symbol is present] , Leo , Virgo , Libra , Scorpius , Sagittarius , Capricornus , Aquarius , Pisces


Type Range & Units Numbered Geometry Location
Ecliptic 0 - 30 Degrees of ecliptic Every 5  Ecliptic ecliptic


There are 28 stars on the rete marked with starsrc=+ipped 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
Pectus Casiop 9.0° of Aries 54° starsrc=+ipped
Triangulus 25.0° of Aries 26° starsrc=+ipped
Caput Gorgonis 12.0° of Taurus 39° starsrc=+ipped
Pleiades 22.0° of Taurus 23° starsrc=+ipped
Oculus [taurus] 4.0° of Gemini 16° starsrc=+ipped
Cingulum Ori 18.0° of Gemini -2° starsrc=+ipped
Venter Leporis 18.0° of Gemini -22° starsrc=+ipped
Canis maior 9.0° of Cancer -16° starsrc=+ipped
Canis minor 17.0° of Cancer starsrc=+ipped
Pollux 19.0° of Cancer 28° starsrc=+ipped
Pectus [cancer] 1.0° of Leo 23° starsrc=+ipped
Lucida Hydrae 14.0° of Leo -5° starsrc=+ipped
Cor [leo] 23.0° of Leo 14° starsrc=+ipped
Dorsum Vrs. ma. 5.0° of Virgo 63° starsrc=+ipped
Dorsum [leo] 10.0° of Virgo 23° starsrc=+ipped
Cauda [leo] 21.0° of Virgo 16° starsrc=+ipped
Algorab 29.0° of Virgo -13° starsrc=+ipped
Cauda Vr. ma. 8.0° of Libra 58° starsrc=+ipped
Pes posterior Vr ma 13.0° of Libra 52° starsrc=+ipped
Aspeta Coro 21.0° of Libra 28° starsrc=+ipped
Alramech 0.0° of Scorpio 19° starsrc=+ipped
Lynx Sep 15.0° of Scorpio -7° starsrc=+ipped
Hasta Bootis 18.0° of Scorpio 42° starsrc=+ipped
Cor [scorpio] 2.0° of Sagittarius -23° starsrc=+ipped
Caput draconis 26.0° of Sagittarius 52° starsrc=+ipped
Scheat Skat 5.0° of Pisces -20° starsrc=+ipped
Venter Caeti 24.0° of Pisces -12° starsrc=+ipped
Caput And 25.0° of Pisces 29° starsrc=+ipped

Nut & Bolt

The rete is attached using a nut & bolt. Brass screw with washer thread into the arm on the back.
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