AS PRACTISED BY THE ARABS. 103 



p". Add together in the Rank of the Cube this product and that 

 upper number, and write the sum opposite to and immediately above them. 

 This sum is now the upper number in the Rank of the Cube. 



q". Multiply the last found figure of the Root into this sum and 

 write the product in the Rank of the Biquadrate opposite to and imme- 

 diately above the upper number in that Rank. 



r" . Add together in the Rank of the Biquadrate this product and 

 that upper number, and write the sum opposite to and immediately above 

 them. This sum is now the upper number in the Rank of the Biqua- 

 drate. 



s" . Multiply the last found figure of the Root into this sum and 

 write the product in the Rank of the Quadratus Cubi opposite to and 

 immediately above the upper number in that Rank. 



t" . Add together in the Rank of the Quadratus Cubi this product 

 and that upper number, and write the sum opposite to and immediately 

 above them. 



u". Transfer this last sum to the right hand one place. This sum 

 so transferred is now the upper number in the Rank of the Quadratus 

 Cubi. 



v". Add the last found figure of the Root to the upper number in 

 the Rank of the Latus, and write the sum opposite to and imme- 

 diately above it. This sum is now the upper number in the Rank of the 

 Latus. 



D 1 



