AS PRACTISED BY THE ARABS. 113 



uJ. Add together in the Rank of the Square 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 Square. 



lS. Multiply the last figure of the Root into the sum, and write the 

 product in the Rank of the Cube opposite to and immediately above the 

 upper number in that Rank. 



J. 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. 



And these operations are analogous to those from h" . to $' . 



*. Add the last figure of the Root to the upper number in the Rank 

 of the Latus, and write the sum opposite to and immediately above it. 

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



. Multiply the last figure of the Rank into this sum, and write the 

 product in the Rank of the Square opposite to and immediately above the 

 upper number in that Rank. 



j. Add together in the Rank of the Square 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 Square. 



And these operations are analogous to those from x," to p". 



*. Add the last figure of the Root to the upper number in the Rank 

 of the Latus, and write the sum opposite to and immediately above it. 

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



