20 



We must tlien Substitute for [X,],„ the final corrected value; 



(15) [K",l^ = [Z'a„ + (/; - /;) y^ {m - 14) 



it being unneccssary to calculatc tlic actual value of rß in seconds of arc to 

 employ this formula. The complète computation of the final corrections [i*^"„J„, 

 roquired by coordinates measured aloug the jn-lines are therefore obtainod by 

 mcans of the formulac numbered (11), (12), (13) and (15). The correspon- 

 ding formulae for the corrections [-fi^",,,],, along the ?i-lines are: 



(11') J,n = G'„, ( 



n-43 



12 



( 1 2') [K^l = E,„ + T„. + J,„ - \p'„l - (P,„ - Pu) + 1 {K + G„) 



(m- 14\ 



(13') [^»a. = {K,.l + \ M [-^^) 



* 



(1 5') [K'\,l = [K,,^,^ + (/; - /;) ^^ (n-43) 



Having deduced the formulae of réduction, we shall now apply them to 

 the actual reseau under discussion. The observed values of E„ and E,„ are 

 set down in Table 4. 



