as ) » c æ 
201 
§. 2 . 
Uc ratio calculi conftaret, rem fequenti modo, ad 
tenorem confvetæ methodi proje&ionum, concipien- 
dam duxi. Exhibeat circulus PQR (Tab. IV. Fig. 3 ) 
difcum Solis, atque ABH hemifphærium Telluris a 
Sole momento conjun&ionis colluftratum, cujus cen- 
trum T fit. Concipiantur a centro Solis Sre&æ du£tæ 
ad fîngula hemifphærii ABH pun£fca, conftituentes 
conum, cujus vertex eft S 8c bafis ABH circulus, 
fiatque hujus coni fe&io plano normaliter du&o 
ad re&am ST , centra Solis & Telluris jungentem, 
atque per femitam apparentem Planetæ in Sole, 
quæ fit FA 7 , transeunte: quo fa£to conftituat fic 
oriundus circulus GFL proje&uram Telluris, cu- 
jus radius CL = parallaxi horizontali Planetæ a 
Sole. Nam du£ta refta CH , & fibi invicem paral- 
lelis re&is CL & TH , nec non LK parallela ipfi 
CT; erit Ang. TCH — parallaxi horizontali Planetæ, 
Ang. TSH — Ang. HLK — parallaxi Solis horizontali; 
adeoque parallaxis horizontalis Planetæ a Sole = Ang. 
CHL — Ang. TCH — Ang. TSH\ At hi Anguli arcus- 
que ipfis refpondentes funt admodum exigui; quare 
parallaxes Planetæ, Solis & Planetæ a Sole, (unt ut re- 
TH , KH & TK— CL refpective. Ut fimul pa- 
tefcat, quid parallaxis efficiat ad accelerandam aut 
retardandam immerfionem & emerfionem Planetæ, 
intelligatur e centro Telluris restas TP, T£>, fe- 
cantes femitam Planetæ in I & £, esfe du&as ad 
limbum Solis, quem Tub toto tranfitu fixum fup- 
pono, Planeta interim motu compofito translato; 
eritque centrum Planetæ in 1 & £, dum dimidia 
fui parte eft immerfus & emerfus. Aft fi ex alio 
hemifphærii Telluris punfto ex. gr. H fpe&etur Sol, 
indeque pariter agantur re&æ HP > HQ ad Solis 
limbum , femitam in T & E' fecantes , erunt JT & 
vol. v. Ce E ET 
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