TARIKH-E ELM
Year:2009 | Volume:- | Issue:8|Papers Count:9

This article sheds light upon a “Chinese” calendar described in the Zij-i Ilkhani. In previous studies, some characteristics of the calendar were ascribed to the “Uighurs” However, I will show that it was not originally associated with the Uighur. This “Chinese” calendar was brought to Iran by the Chinese Taoist Fu Mengchi who accompanied his ruler Hulegu. Fu Mengchi informed Nasir al-Din Tusi of the Chinese calendrical system, which Tusi described in his Zij-i Ilkhani. Soon afterward, the calendar was included in the zij of Muhyi al-Din Maghribi, because it was only used among the Mongol ruling class and their Buddhist servants, who were called Uighur. Muhyi al-Din labeled the “Chinese” calendar the “Chinese-Uighur” calendar, and this title was repeated in subsequent zijes. Therefore, modern scholars have regarded the calendar as a product of the Uighurs. However, the title “Uighur” attached to the calendar in later zijes does not reflect the characteristics of the calendar, but rather the circumstances in which it was utilized.

Here is an attempt to present the ideas concerning the Medieval Persian and Arabic calendars as offered in the works of the 7th century A.D. Armenian scientist Anania Shirakatsi. The calendars of Christian Persians and Arabs, as explained in Anania’s work, are of the Julian type, with 365.25 days per year. By Persian and Arabic Calendars, he means variants of the Julian calendar used by groups of Christians living in the Persian and Arabic lands. These calendars had a structure very different from what is generally known as Arabic or Islamic and the traditional Persian calendar.

Trisection of an angle is one of the famous problems in the history of mathematics. The impossibility of trisecting an angle with a straightedge and compasses was known. Therefore finding an accurate approximation of irrational quantity of the Sine of degree- which was important for setting up sine tables in Zijes, and also for astronomical calculations- is very difficult. So, many scientists devoted their attempts to find a solution to this problem. Mirza Abu Torab Natanzi, a scholar of the Qajarid era, in a Persian treatise entitled Dar ma‘rifat-i watar-i thulth-i qaws-i ma‘lumat al-watar (on the knowledge of the chord of one-third of an arc with a known chord), presented a geometrical method for trisecting an angle which turns out to be mathematically equivalent to the algebraic method of Jamshid Kashani (al-Kashi) for finding the Sine of one degree. Surveying different approximate methods of trisecting an angle in ancient Greek and Islamic periods, this paper presents a critical edition and a commentary of Mirza Abu Torab’s treatise.

In the veterinary texts of the Islamic period, we frequently encounter the word Qeysar, which is an animal disease and specially has been well described in horses. It is characterized by muscular contractions, the retraction of the third eyelid, dysphasia and other symptoms that have been mentioned in the veterinary literature of Islamic period manuscripts. Considering these symptoms and some evident similarities, we have tried in this study to compare Qeysar with Tetanus. Our methods are etymological and historical studies of these three words (Qeysar, Kozaz and Tetanus), in classical Arabic, Persian and also western (Roman and Greek) sources. According our knowledge, this is the first scientific study of Qeysar in the view point of pathology and etimology of this disease.

The main problem of Ptolemaic model of the superior planets was related to the “equant point”. It is a geometrical point with respect to which the motion of the deferent sphere is uniform. But it cannot be acceptable on the basis of Aristotle's philosophy on the motions of celestial spheres. Astronomers of Maragha School devised some new models to avoid this problem, while they were in accordance with Ptolemy's observations. Qutbal-Din Shirazi (d. 1311) has provided his own model for superior planets in his works: Nihayat al-idrakfi dirayat al-aflak and al-Tuhfa al-Shahiyya in Arabic, and Ikhtiarat-i Muzaffari in Persian. His model in Ikhtiarat has not been studied yet and it is different from the one introduced by Saliba (1979) and Kennedy (1966). Here, I introduce Qutb al-Din's model for superior planets provided in eighth chapter of the second book of Ikhtiarat-i Muzaffari. I also discuss a conflict between observations and the theory which this model involves.

‘Abd al-Rahman al-Sufi is a well-known astronomer who has some works in astronomy, mathematics and alchemy. The importance of his Suwaral-Kawakib (book about the constellations) caused that researchers don’t practice his other works. Four treatises on astrolabe are ascribed to al-Sufi, any one of them is in Persian. Attribution of the three Arabic treatises among these four to him is certain. In this article, besides providing a critical edition of the Persian text, its contents are compared with the Arabic versions.

This is an unpublished work by the late Dr. Hooshang A‘lam on Ibn Farighun’s Djawami‘ al-‘ulum. The work has been written in French and translated into Persian by Mrs. Negar Naderi. The scan copy of Dr. A’lam’s handwriting is provided at the end of the article.