214 PROCEEDINGS OP THE AMERICAN ACADEMY 



z-{-X= 23".0144 (f —t ) — 0".0115 {f -\-t)— 0".000056 t'^ 



— 0".000210 fi 



z'—l' = 23".0144 {t' — + 0".0115 QJ + + 0".000210 f^ 



+ o".ooooo6 e 



6 = 20".0652 {f — t)— 0'-.000048 f^ -f 0".000048 f 



a =■ a -\- z --\- X 



cos fi' sin a' = cos 8 sin a 



cos 5' cos a' = cos d cos a cos ^ — sin 5 sin 



sin 8' = cos 5 cos a sin ^ -|- sin d cos S 



a' = a' -\- z' — X' 



Using Struve's constants, the values become : — 



z -^1 = 23".0311 (f — — 0".0001922 f — 0".0000497 r- 



z' — l'= 23 .0311 (f — t)-{-0 .0000497 t^ -\- .0001922 t'^ 



d =20 .0611 {f — ^) -1- .0000432 t^—O .0000432 r^ 



According to Bessel IL, the formulae for the computation of these 

 quantities are, — 



I = 0".17926 t — 0".0002660394 t^ 



w = 23°28'18".0 4- 0".00'000984233 t^ 

 ifj = 50".37o72 t — .0001217945 f-; 



1', co', and t/;', are the same functions of t'. 



\ (z' — z) = 0".1011804 {f + + 0".0000002446 (f + ty 



9 



tan i (.'+.) = <^o.i (.' + .) ^^^ ( , _ ) 

 cos i (w' — w) 



tan i ^ = sm|_(^Mi£) tan i (co' + «) 



^ cos ^ (3/ — ^) ^ ^ ^^ ^ 



The time is counted from 1750. 



According to Struve and Peters, the time is counted from 1800, 



and X = 0".15119 t — 0".00024186 t^ 



03 = 23°27'54".45 + .00000735 t'^ 



xfj= 50 .3798 t — .0001084 t"^ 



i («' — s) =0 .075573 (f + t) 



+ .0000001 G26 (^' + 0'' 



