Astrolabe Catalogue


Front of astrolabe without rete or plates. 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 throne is of the simple type with s-shaped scroll work support(s). The throne is attached with a integrated base. The throne is engraved on both sides with dedications to Queen Elizabeth. Markings:
Content Translation Notes Type
Elizabeth Dei Gratia Anglii Franciae & Hiberniae Regina etc Dedication
ER Owner's mark


The mater and limb are of three pieces construction. . Scales on the limb:
Type Range & Units Numbered Geometry Location
Equal hours I - XII Times of day I- xii in roman numerals hours Circular, concentric None
Degree 0 - 360 Degrees Every ten degrees Circular, concentric None


The womb contains an elaborately labelled windrose and 'Quadratum Nauticum'.
The womb contains 2 scales of the following types:
Type Range & Units Numbered Geometry Location
Windrose North - North Direction Not numbered  Box None
Quadratum nauticum 0 - 90 Degrees Every 10 degrees Box None
The womb is inscribed:
Content Translation Notes Type
Thomas II 1559 Thomas Gemini 1559 Maker's signature
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