Astrolabe Catalogue

astrolabe, inventory number 35313 from Iṣfahān, ca. 1700
thumbnail for astrolabe (front), inventory number 35313 from Iṣfahān, ca. 1700
thumbnail for astrolabe (back), inventory number 35313 from Iṣfahān, ca. 1700
thumbnail for astrolabe (rete front), inventory number 35313 from Iṣfahān, ca. 1700
Dateca. 1700
MakerKhalīl Muḥammad ibn Ḥasan ‘Alī
Inventory no.35313
AcquisitionPresented by J. A. Billmeir in 1957

Although it is difficult to determine when, it is clear that the original rete of this astrolabe was lost and the present one is a later replacement. The smaller pieces of an astrolabe, such as the horse and the pin, were regularly lost and replaced. But even major components were sometimes mislaid or broken and would have to be replaced.

The most obvious indication that this rete is not original to the instrument is the relatively crude workmanship. Whereas the rest of the instrument has a finished and elegant look, the rete appears to have been quickly made. The radial lines delimiting the zodiacal houses cut across the ecliptic and the outer tropic band. Further, the zodiacal signs on this rete are divided every 30°, as if the ecliptic was co-planar with the equator. Khalīl Muḥammad ibn Ḥasan ‘Alī divided his ecliptic as if it were inclined 23.5°. Additional construction marks can be seen on the ecliptic and horizontal straps. The star pointers are roughly cut, and lack any names, which gives the rete an unfinished appearance. Finally, the script differs in style and execution from the rest of the instrument.

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Throne, Ring and Shackle

The throne is of the indo-persian, pierced type made of brass attached with integrated base made of brass and has a simple, squared cross-section ring made of brass and omega type shackle made of brass . More information


The mater and limb are of one-piece construction. The tab to keep the tympans in place is located at the bottom of the instrument, 180° from the throne. Scales on the limb: degree scale.

The limb is inscribed: with a marked as [inscription on edge of limb]. [ pending ]. More information


The back contains 17 scales of the following types: Altitude; Declination; Azimuth of Qibla; Altitude of noon sun; Sine/Cosine; Unequal hours; Cotangent; Terms; Zodiacal signs; Faces; Lunar Mansions; Shadow square; Triplicities. The back is inscribed: with a maker's signature marked as نمقه العبد عبد الائمة (Embellished by the servant ʿAbd al-Aʾimmah). Inscription in cartouche. with a miscellaneous marked as غرض نقشيست كه تا باز ماند كه هستي را نمى بينم بقائي (The aim of the engraving is that it should remain after me, for I see not the continuity of earthly existence.). Inscription at bottom edge. More information

Rete, Pin & Horse

The rete contains 19 stars. The rete is a replacement. The zodiac on the rete is labelled: الحمل , الثور , الجوزا , السرطان , الاسد , السنبله , الميزان , العقرب , القوس , الجدي , الدلو , الحوت .
The rete is attached using a pin & horse. The head of the pin is decorated with radial lines. The horse is unusual in that there is the head of a duck immediately behind the horse's head. There is a flower-shaped spacer between the horse and the rete. Like the alidade on the back, this is a later replacement.. More information


There are 7 plates with latitudes ranging from 11°0' to 40°0' . More information

Rules & Alidades

Type Details
AlidadeDouble-ended. The rule is not original. This is a later addition to the instrument and bears no markings or scales.
More information


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