1TJ __ T J I X 2 __ I X 2 



x I (xi •+>»*) (*/ + y/ + i) I/2 (*.»+y. B ) 



/?2 



-/ 



(*. 8 +V+-0 



Z 2 Xj I*Xj 



— r^ 3- ^ 



(x/ + y,«) (x/ + y,« + 2) i /« ( Xi « + ya «) 



Using H z given by formula (51) we have for H 



p-mHyn — yi) (58) 



IH X + 77//, = / 



^ (*** + y,«) (x 8 * + y,« + 7) J'2 (x/ + y ,8) 



2/n w 2 x 2 



(*,« + y 3 2 + 2) ' /2 (y 3 2 + i) (x 2 * + y, 2 + 7) llz 



\same expression with x s \ 

 ~ L \replaced by x t ] \y* — yi) ( 59 ) 



The expression g(x,y) to be mapped is either of those within the brackets 

 with the subscripts omitted. A map for the case of I inclined 60° may be plotted 

 from the values given in Tables 27-IX. Such a map is shown in Figure. 27-15. 



611 



