HISTORY OF ALGEBRA, JG7 



i 



astrolabe. In this list of his works, no notice is taken of his great ire-s^ 

 tise on Algebra, the Behr-ul-Hisab, which is alluded to in the Khulasat- 

 wl-Hisab. Maulavi Koshen Ali tells me the commentators say, it is 

 not extant. There is no reason to believe that the Arabians ever knew 

 more than appears in Baha-ul-d1n's book s for their learning was at its 

 height long before his time. 



From what has been stated it will appear, that from the Khuldsat-u!~ 

 Hisdb, an adequate conception may be formed of the nature and extent of 

 the Algebraical knowledge of the Arabians ; and hence I am induced to 

 hope that a short analysis of its contents will not be unacceptable to the 

 society. I deem it necessary here to state, that possessing o nothing more 

 than the knowledge of a few words in Arabic, I made the translations, 

 from which the following summary is abstracted, from the viva voce in- 

 terpretation into Persian of Maulavi Roshen Ali, who perfectly under- 

 stood the subject and both languages, and afterwards collated it with a 

 Persian translation, which was made about sixty years after Bah v a-ul- 

 bin's death, and which Roshen Ali allowed to be perfectly correct. 



The work, as stated by the author in his preface, consists of an in- 

 troduction, ten books and a conclusion. 



The introduction contains definitions of arithmetic, of number, which 

 is its object and of various classes of numbers. The author distinctly 

 ascribes to the Indian sages the invention of the nine figures, to express 

 the numbers from one to nine. 



Book i, comprises the arithmetic of integers. The rules enumerated 

 under this head are Addition, Duplation, Subtraction, Halving, Multi- 

 plication, Division, and the Extraction of the Square Root. The method of 



