267 



Scheme of Calculation employed by Mr Graham. 



Let 6r denote the number in the n-mth vertical line and in the nth horizontal line of 

 the following scheme, where m varies from n 1 to 1 and n takes successive integral values 

 +i _^n_ L _(n-ml)(n m) rim+l ___., / __ I ,\ /3 i_ /3 _ J 



n n-m = 



2 M = 



3 M = 



4 M = 



5 = 



6 M = < 



8 ,,= ( 



9 ,,= 08 



10 



342 



