I was introduced to Tiisi: and his Tadhkira some 19 years ago. That first meeting was neither happy nor auspicious. My graduate student notes from the time indicate a certain level of confusion and frustration; I seem to have had trouble with such words as tadwlr (epicycle), which was not to be found in my standard dictionary, and with the concept of solid-sphere astronomy, which, when found, was pooh-poohed in the standard sources. I had another, even more decisive reaction: boredom. Only the end of the term brought relief, and I was grateful to be on to other, more exciting aspects of the history of science. A few years later, I found myself, thanks to fellowships from Fulbright-Hays and the American Research Center in Egypt, happily immersed in the manu script collections of Damascus, Aleppo, and Cairo. Though I had intended to work on a topic in the history of mathematics, I was drawn, perhaps inevitably, to a certain type of astronomical writing falling under the rubric of hay' a. At first this fascination was based on sheer numbers; that so many medieval scientists could have written on such a subject must mean something, I told myself. (I was in a sociological mode at the time.

I was introduced to Tiisi: and his Tadhkira some 19 years ago. That first meeting was neither happy nor auspicious. My graduate student notes from the time indicate a certain level of confusion and frustration; I seem to have had trouble with such words as tadwlr (epicycle), which was not to be found in my standard dictionary, and with the concept of solid-sphere astronomy, which, when found, was pooh-poohed in the standard sources. I had another, even more decisive reaction: boredom. Only the end of the term brought relief, and I was grateful to be on to other, more exciting aspects of the history of science. A few years later, I found myself, thanks to fellowships from Fulbright-Hays and the American Research Center in Egypt, happily immersed in the manu script collections of Damascus, Aleppo, and Cairo. Though I had intended to work on a topic in the history of mathematics, I was drawn, perhaps inevitably, to a certain type of astronomical writing falling under the rubric of hay' a. At first this fascination was based on sheer numbers; that so many medieval scientists could have written on such a subject must mean something, I told myself. (I was in a sociological mode at the time.

I was introduced to Tiisi: and his Tadhkira some 19 years ago. That first meeting was neither happy nor auspicious. My graduate student notes from the time indicate a certain level of confusion and frustration; I seem to have had trouble with such words as tadwlr (epicycle), which was not to be found in my standard dictionary, and with the concept of solid-sphere astronomy, which, when found, was pooh-poohed in the standard sources. I had another, even more decisive reaction: boredom. Only the end of the term brought relief, and I was grateful to be on to other, more exciting aspects of the history of science. A few years later, I found myself, thanks to fellowships from Fulbright-Hays and the American Research Center in Egypt, happily immersed in the manu script collections of Damascus, Aleppo, and Cairo. Though I had intended to work on a topic in the history of mathematics, I was drawn, perhaps inevitably, to a certain type of astronomical writing falling under the rubric of hay' a. At first this fascination was based on sheer numbers; that so many medieval scientists could have written on such a subject must mean something, I told myself. (I was in a sociological mode at the time.

I was introduced to Tiisi: and his Tadhkira some 19 years ago. That first meeting was neither happy nor auspicious. My graduate student notes from the time indicate a certain level of confusion and frustration; I seem to have had trouble with such words as tadwlr (epicycle), which was not to be found in my standard dictionary, and with the concept of solid-sphere astronomy, which, when found, was pooh-poohed in the standard sources. I had another, even more decisive reaction: boredom. Only the end of the term brought relief, and I was grateful to be on to other, more exciting aspects of the history of science. A few years later, I found myself, thanks to fellowships from Fulbright-Hays and the American Research Center in Egypt, happily immersed in the manu script collections of Damascus, Aleppo, and Cairo. Though I had intended to work on a topic in the history of mathematics, I was drawn, perhaps inevitably, to a certain type of astronomical writing falling under the rubric of hay' a. At first this fascination was based on sheer numbers; that so many medieval scientists could have written on such a subject must mean something, I told myself. (I was in a sociological mode at the time.

Tusi (1201-1274 a.d.) was an Arabic scholar whose writings became the standard texts in several disciplines for several centuries. They include editions of Euclid's Elements and Ptolemy's Almagest, as well as other books on mathematics and astronomy, and books on logic, ethics, religion. He wrote the Tadhkira, to be "a summary account of `astronomy' presented in narrative form. The details are expounded and proofs of the validity are furnished in the Almagest. Indeed, ours would not be a complete science if taken in isolation from the Almagest for it is a report of what is established therein." It is thus not only a sort of running commentary on the Almagest, but also an account of medieval Arabic cosmology. Jamil Ragep has not only translated the text of the Tadhkira, but has also provided a lengthy introduction with a biography of Tusi and a discussion of the context in which the Tadhkira was written and its influence, as well as a detailed and thorough commentary on each section of the text.

This book provides the first presentation of the bilingual textual material that illustrates the transmission of Islamic astronomy to scientists of the Indian Sanskritic tradition. It includes editions of the chapter of the "Tadhkira" in which the mid-thirteenth century Persian astronomer, Nas?r al-d?n al- s? discussed the new solutions that he devised to overcome certain technical problems in the lunar and planetary models of Ptolemaic astronomy and of the learned commentary composed by al-Birjand? in the early sixteenth century together with the Sanskrit translation of both made by Nayanasukha at Jaipur in 1729. An English translation of the Arabic texts and a commentary discussing their technical meanings and the deviations from them in the Sanskrit version together with a glossary of the Arabic and Sanskrit technical vocabulary conclude the volume.