The Astrolabe was made by Johann Anton Linden in the year of 1580, Heibronn. It was originally constructed with brass. It was firstly presented by Lewis Evans in the year of 1924.
My copy of this astrolabe is made with paper. It comes with a rete of the heart-shape, a rete for 39 stars. The zodiac on the rete is labelled: 1 ARIES , 2 TAVRVS , 3 GEMINI , 4 CANCER , 5 LEO , 6 VIRGO , 7 LIBRA , 8 SCORPIO , 9 SAGITTARIVS , 10 CAPRICORNVS , 11 AQVARIVS , 12 PISCES. It was hand drawn with pencil on two-ply paper.
There are two steps using this astrolabe to tell the time. First you need to observe the star during the night to set the astrolabe.First use the back of the astrolabe to point the star. When it is aligned read the matching zodiac on the zodiac on the zodiac scale. It shows the position of the sun at that day. Second, turn to the front of the astrolabe and locate the position of the star on the ecliptic ring on the rete then use the ruler to align with that point. Third, fix the ring and the rete, turn the ruler so it points to a time of that night. Then the astrolabe is settled.
The second step is to observe the sun during the day to tell the time.First hang the astrolabe by its throne to align it perpendicular to the ground. Use the calendar scale and zodiac scale at the back to convert the given date to zodiac. Second, use the alidade to point the sun using the two sights to make sure that their sight hole aligns. When they align mark the altitude using the elevation scale at the outer rings. Locate the star of interest on the star pointer as a reference point on the front. Third, rotate the rete and locate it on the altitude. Last, rotate the ruler so it points to the zodiac on the ecliptic ring on the rete.
Then you can read the time from the other end of this ruler.