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 Z?jes, and also for astronomical calculations- is very difficult. So, many scientists devoted their attempts to find a solution to this problem. M?rz? Ab? Tor?b Nat?anz?, a scholar of the Qajarid era, in a Persian treatise entitled Dar ma‘rifat-i watar-i thulth-i qaws-i ma‘l?mat 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 Jamsh?d K?sh?n? (al-K?sh?) 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 M?rz? Ab? Tor?b’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, Koz?z 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-D?n Sh?r?z? (d. 1311) has provided his own model for superior planets in his works: Nih?yat al-idr?k f? dir?yat al-afl?k and al-Tuh?fa al-Sh?h?yya in Arabic, and Ikhti?r?t-i Muz?affar? in Persian. His model in Ikhti?r?t has not been studied yet and it is different from the one introduced by Saliba (1979) and Kennedy (1966). Here, I introduce Qut?b al-D?n's model for superior planets provided in eighth chapter of the second book of Ikhti?r?t-i Muz?affar?. I also discuss a conflict between observations and the theory which this model involves.

Abd al-Rah?m?n al-S??f? is a well-known astronomer who has some works in astronomy, mathematics and alchemy. The importance of his S?uwar al-Kaw?kib (book about the constellations) caused that researchers don’t practice his other works. Four treatises on astrolabe are ascribed to al-S??f?, 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.

Ibn Far?gh?n’s Djaw?mi‘ al-‘ul?m Hooshang A‘lam Ibn Far?gh?n’s Djaw?mi‘ al-‘ul?m Hooshang A‘lam This is an unpublished work by the late Dr. Hooshang A‘lam on Ibn Far?gh?n’s Djaw?mi‘ al-‘ul?m. 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. This is an unpublished work by the late Dr. Hooshang A‘lam on Ibn Far?gh?n’s Djaw?mi‘ al-‘ul?m. 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.

در این مقاله برآنیم تا تقویم‌های ایرانی و عربی را که آنانیا شیراکاتسی، دانشمند سد? هفتم میلادی ارمنستان، در آثار خود آورده است، بررسی کنیم. تقویم‌های مسیحیان عرب و ایرانی که در کارهای آنانیا به آنها اشاره شده است بر اساس تقویم یولیانی، 365 روز و ربع روز به ازای هر سال هستند. او با استفاده از تقویم‌های ایرانی و عربی، تغییراتی را که مسیحیان ساکن در سرزمین‌های ایرانی و عربی در تقویم یولیانی داده بودند بیان کرده است. این تقویم‌ها با آنچه معمولاً به عنوان تقویم عربی (اسلامی) یا ایرانی شناخته می‌شوند، بسیار متفاوتند.

این مقاله به «تقویم چینی» که در زیج ایلخانی از آن یاد شده است، خواهد پرداخت. در تحقیق‌های پیشین برخی مشخصه‌های این تقویم به «اویغورها» نسبت داده شده و در اینجا من نشان می‌دهم که این تقویم ربطی به اویغورها ندارد. این تقویم چینی را یک تائویست به نام فو منگشی که به همراه هولاکو به ایران رفته بود، و نصیرالدین طوسی در زیج ایلخانی از او یاد کرده، به ایران برده است. بعداً هم به عنوان تنها تقویم مورد استفاد? مغول‌ها و اویغورها، در زیج محی‌الدین مغربی آمده است. محی‌الدین مغربی عنوان «تقویم چینی» را به «تقویم چینی- اویغور» مبدل کرد و این در زیج‌های بعدی نیز تکرار شد، از این رو محققان امروز آن را تقویم اویغوری می‌نامند. هر چند اطلاق عنوان اویغوری برای این تقویم در آثار بعدی، مشخصه‌های اصلی آن را تغییر نداد اما تغییراتی در کاربرد آن به وجود آورد.