tio noftri indiiet hanc formam: L" — rjT^^^I^ , qiwe intcgrata 

 dat / fl =r 5 A fin. i? — 5 A fin. -£-, fiiie / 4- z= c7. A fm. iL, vbi ^ 

 fit parametcr variabilis Traiedoriarum. Quia autem hinc fit 

 xx-hjj-aa^ erit a-]/(xx-i-jj)^ qui valor in aJtervtra aequatione 



fubllitutusdat-^^^ = fm.^ i. / llJi^JJ , fuic fin ^? — 



^ / V{xx-hyy)^ q^,^(. gj.gQ ^fj. acquatio intcr jr et j/ pro Traicdo- 



riis. Ex ipfa autcm aequationc propofita j =r V (a a — x x) 

 cius valorcm a zrzV (x x -{-jj) fubllituamus, quem breuitatis 

 gratia ftatuamus - z^ eritquc pro Traicdoriis /-^ :r= 5 A fin. -^, 

 ■vbi, fi porro CP fit ille angulus, cuius finus eft -1, fict /-|- =: 5 (p • 

 Cum igitur z dcnotct diftantiam pundi j a ccntro C, (|) autcm 

 complementum anguli, qucm hacc rccfla cum axe conftituit ; eui- 

 dcns etl logarithnuim diltantiac ::; proportionalcm etrc ifti angu- 

 lo, in quo confillit indoles Spirahum logarithmicarum. 



Exempkim 5. 



Fig. a. ^. i5. Sint nunc curuac fccandac omncs circuH , fefc 



in ipfo pundo A tangentes, quae hac aequationc exprimantur: 

 ^:=zy/i2ax-xx), ct cum fit dj = tiff^^i±±ll, erit 



p — __l:rJL-. ct qzzz - — ^ , 



y Vl = a:c.-.xj.-) ■' \[2ax — xxi^ 



hincque i -\-p p = "^ 7 vndc pro Traicdoriis habebitur 



haccaequatio: ^7^^;^:^ — »a;c-;cx-6Ta-^!/..ax-^x) ■> ^*"*^ 

 xda/ {2 a X — a* .v) — 5 ( « — x) xd a =zh a ad x , 



quac aequatio cum fit homogcnca, ponatur x-at, vnde hacc 

 prodibit aequatio : 





quac 



