-== Cl2p) === 



§. 4. Sit niinc wQ« proiedio Paralleli MN, pcrTalj. IT. 

 cuius pundum Q ponatur planum LQ/ bafi coni MON pa- F'g- 12 

 rallelum; eritque LQ^l circulus, ideoque dudla Q^ ad L/ et 

 fn n normali , fiet Q_q^ :zzh q . q l. At , literis hic idem de- 

 notantibus ac in Fig. lo. eft mc:Mc-mq'.Lq., et nc :'^czznq:qly 

 unde poiitis Q^q zzz tt , m q zzz t^ m n zzz. 1 cl ., erit 



tt M =r ?!:£ . ^ . f (2 a — , ftu 



mc 71 c ^ ^ ' 



a z + 2 z 2' ftn. (3'/"i- $^ + z' z' (/Ji». p^ — cof.^ <h') t f n » A 



: (T7^:T5'-+-a'J;n.$)' ^ ^ "^ ^^ * 



Reperitur autem 



g 2 ■z-' coj. (I); ( z//r'. p^ 4- %' jin. CpQ 



[zH-z-^co/. ((3--$')] [;& — 2'co/. i,3'-f-Cp')]* 



Quo valore introducflo habemus 



^ „ a a g 2 g^ 2^ co].'^ <^' (za.i ^—\ i) . 



aa [si-i-z-tcoj.p'— $•-)] [z >- 2' co/. (P' -f- Cp')] ' 



tinde perfpicitur , proiedionem efle ellipfin , cuius femiaxis 

 transverfus ^= a , coniugatus vero =z 



(3 -^ a 2 s' co^. (^' gf 



^ y [2 -H z'co/. ((3' — $■')] [2 — z' co/. f3'-hCp-')] 



PP — _ B_ __ [ 2-f- Z^Cof. (P- CPM] [2 ^2^C0f. (|3'-KCt)^l] 



aa A (z/m. P'-)- 2'/"i- '?>')'' 



z 2 -t- 2 2 2' /m. p-' /m. CP' -)- 2^ 2' (/zn". <^' — cof°. p-'^ 



Hic fi numerator B a denominatore A fubtrahatur , fiet 



A — B =z cof.^ p^ (zf z'~z s). 



Ergo a. efl: axis maior et p axis minor , h. e. axis transver- 

 fus verticcsque ellipfeos cadunt in ipfum Meridianum ^« pundi 

 Zenith (Fig. lo.), quando z'^z., feu (p< p. IHi autem Pa- 

 ralleli , quorum latitudo maior efl: ktitudine pundi Zenith , 

 proiiciuntur in ellipfes, quarum axes coniugati coincidunt cum 

 Meridiano q n , axes autcm transverfi ad Meridianum Zenith 

 Noua Aaa Acad, Imp. Sc, T, VU R fiunt 



