A PERSIAN ASTROLABE MADE BY NAJM AL-DIN MUHAMMAD MUNAJJIM IBN IMAM ALI IBN BAYAZID IBN SAYYID HASAN AJAM SEYYID MUHAMMAD AL ABBASI, 16TH CENTURY

Persian astrolabe made by Najm al-Dīn Muḥammad Munajjim Ibn Imām ‘Alī ibn Bayazid ibn Sayyid Hasan ‘Ajam Seyyid Muhammad al-‘Abbāsī.
Brass, 16th century
Length: 24.5 cm.
Diameter: 18.8 cm.

THE FRONT OF THE MATER
The mater in engraved with a gazetteer. The gazetteer consists of two sets of 5 concentric circle bands. The first row of the first circle band on top left to the center line reads: Buldān (Locality), Tūl ( Longitude), ‘Arḍ (Latitude), Saat ( Maximum Hours of Daylight for that Locality) and the Inhiraf ( The direction to Mekka,). Interestingly the bands dedicated to “hours” and “inhiraf” are empty. This is also the case for the second set of concentric circles.

Along the rim there are two degree scale which run from 0° until 360° in increments of 1 and in 5 degrees. Only the 5 degree divisions are labeled, where the labels are as follows:

Along the rim, only the values of the 100° increments are written in full abjad numerals.
Probably to save space, the ten degree increments run recurrently from [ 0° until 90°].
For the 5 degree increments only the abjad value “5” is used, thus 5, 85, 215 are all labeled as the abjad letter “ha”.