INVENIENDI PARALLAXIN SOLIS. 325 



foitis corredionibus x et y erit vera dirtantia O ? 

 = j--f-A:cof.(rH-7. fin.o". Verus autem angulus $OV, 

 ftatuatur (T-{-d<T et qiium fit tang. ( o- H- ^ (T ) 

 =: 4- -'-^^-t,±^ =: tang. o- -f- ,-fV , ob tang. 

 G-=:-Si^l^^, colligitur J^— -f-^^^^-t:^ , 

 quum autem fit l -\- y t — s f n. cr et — (ct H~ §) ? 

 ^ J- cof. 0- , erit 4^, ::^ y^J^^^^'h^ ideoque 

 ^ ^ a_ j^q/;^o;^-^?ri^ ^ ita \t habeatur verus angulus 



V. Saepe etiam vtile erit noffe variationem 

 Tnomentaneam , quam patiuntur diftantia G ? et 

 fingulus ^OV in qua inueftigatione corrediones x 

 etj negligcre licebir. Sit igitur tempus ab epocha 

 elapfum zi: t -\-- d t horarum et quum fit ss 



— (a-1- (3 )';?-]-(/ -4- y?)' erit differentiando sds 



— (a-i-(3)'^^^-f-'y(/+y t)dtzz — (a ^ (^) s d t cof o- 

 "{- y s d t. fin, cr, ideoque d s zz ~ (a 4- |3) d t coC. <t 

 ^ y d t Cm. CT f coniunclim ergo elapfo tempore 

 t -{- d t , erit vera diftantia centrorum O ? =r j* 

 4- X cof cr -i-j' fin. ct — (a-l-(3) ^^cof.cr-|-y^;fm. cr, 

 deinde quum fit rang. ct zr -l^lt^^ , variato ^ pro- 

 dit 4^^ = rJMr-,, vnde fit ^^^^(«d^PliA.^, ex quo 

 nancilcimur verum angulum ? O V n <r + ^^-±^^^-^* 



^ co/. (T — X fin. (7 _ I y coj. g- — -x fin. g- |_ f« -f- ^) fhus ^ * 



Ss 3 SECTIO 



