This instrument is clear evidence of the links between the astrolabe and astrology. On one side is an astrolabe for a single latitude, and on the other an astrological volvelle, used to find the positions of planets and other celestial bodies, especially in relation to the traditional astrological houses.
1570: A rare 16th century gold sundial and compass ring, possibly German, The hinged oval bezel designed as a seal and engraved with a coat of arms, opening to reveal a sundial and compass, on a plain gold hoop, dimensions of bezel 1.8x2.0cm
An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (in the celestial sphere), consisting of a spherical framework of rings, centred on Earth, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. Read more on wikipedia.
Shipwreck found with Viking sun stone An oblong crystal found in the wreck of a 16th-century English warship is a sunstone, a near-mythical navigational aid said to have been used by Viking mariners, researchers said on Wednesday.