AL KHA.ZINİ'S TREATISE ON ASTRONOMICAL INSTRUMENTS

From Houzeau and Lancaster 1 one may gain the impression that Al Khazini's book on astronomical instruments were extant. A study of their sources 2 shows, however,' that their particular phraseology is traceable to D'Herb ot, who heavily draws upon Haj i Khalifa, And it is quite certain that the statetement of D'Herbelot to the effect that -such a book exists "in the Arabic libraries" means nothing more than the occurrence of the name of such a book in Haji Khalifa.f There is at least another source statement concerning this book.s and apperently later occidental notices 5 conceming it are based upon one or the other of these sources. Brockelmann clearly states that the book is lost. 6 As I had privately indulged in some speculation concerning the content of this bo ok and on the possibility of its containing certain items of information much needed for the history of Islamic observatories, it was a very pleasant surprise to me to find it in the Library of the Sipahsalar Mosque in Tehran. The book which I havefound is entitled "Risdla fi'l dldt", The title of Al Khazini's lost book is specified in the above mentioned sources as "Alat al 'ojıba al raşadiya", The two works may therefore not be the same, but even then, with the Sipahsalar manuscript we are clearly in possession of a work which contains Al Khazini's knowledge and ideas on astronomical instruments and which was so far not known to have come down to us. The manuscript in question is in Arabic. It consists of 34 pages, and is legibly written and well preserved. The first leaf, i.e., the first two pages, is bound in the volume registered under number 682 and forms the first leaf of that volume. The remaining 32 pages are in volume No. 68ı and are bound as thefirst 32 pages of that volume. As the first two pages which are in 682 contain the tit1e, name of author, and list of contents, and as the content of the remaining pages is in full agreement with this table of contents, there is no room for doubt that these are the two parts of one and the same