مجله تاریخ علم
سال هفتم شماره 1 (پیاپی 8، بهار و تابستان 1388)

Trisection of an angle is one of the famous problems in the history of mathematics. The impossibility of trisecting an angle with a straightedge andcompasses was known. Therefore finding an accurate approximation of irrational quantity of the Sine of degree- which was important for setting up sine tables in Zījes, and also for astronomical calculations- is very difficult. So, many scientists devoted their attempts to find a solution to this problem. MīrzāAbūTorābNatanzī, a scholar of theQajarid era, in a Persian treatise entitled Darma‘rifat-i watar-i thulth-i qaws-i ma‘lūmat 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 JamshīdKāshānī (al-Kāshī) 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 MīrzāAbūTorāb’s treatise.

In the veterinary texts of the Islamic period, we frequently encounter the word Qeysar, 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 Qeysar with Tetanus. Our methods are etymological and historical studies of these three words (Qeysar, Kozāz and Tetanus), in classical Arabic, Persian and also western (Roman and Greek) sources. According our knowledge, this is the first scientific study of Qeysar 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. Qutb al-DīnShīrāzī(d. 1311) has provided his own model for superior planets in his works: Nihāyat al-idrākfīdirāyat al-aflāk andal-Tuhfa al-Shāhīyya in Arabic, and Ikhtiārāt-i Muzaffarī in Persian. His model in Ikhtiārāt has not been studied yet and it is different from the one introduced bySaliba (1979) and Kennedy (1966). Here, I introduce Qutb al-Dīn's model for superior planets provided in eighth chapter of the second book of Ikhtiārāt-i Muzaffarī.I also discuss a conflict between observations and the theory which this model involves.

‘Abdal-Rahmānal-Sūfī is a well-known astronomer who has some works in astronomy, mathematics and alchemy. The importance of his Suwar al-Kawākib (book about the constellations) caused that researchers don’t practice his other works. Four treatises on astrolabe are ascribed to al-Sūfī, 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. HooshangA‘lam on IbnFarīghūn’sDjawāmi‘ al-‘ulūm. The work has been written in French and translated into Persian by Mrs. NegarNaderi. The scan copy of Dr. A’lam’s handwriting is provided at the end of the article.

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 AnaniaShirakatsi. 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.

This article sheds light upon a “Chinese” calendar described in the Zīj-i Īlkhānī. 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 Hülegü. Fu Mengchi informed Nasīr al-DīnTūsī of the Chinese calendrical system, which Tūsī described in his Zīj-i Īlkhānī. Soon afterward, the calendar was included in the zīj of Muhyī al-DīnMaghribī, because it was only used among the Mongol ruling class and their Buddhist servants, who were called Uighur. Muhyī al-Dīn labeled the “Chinese” calendar the “Chinese-Uighur” calendar, and this title was repeated in subsequent zījes. Therefore, modern scholars have regarded the calendar as a product of the Uighurs. However, the title “Uighur” attached to the calendar in later zījes does not reflect the characteristics of the calendar, but rather the circumstances in which it was utilized.