X -4- jr rr X ( cof. ^ cof. r — cof. » fin. ^ fin. r) 



+ Y (fin. ^ cof. r + cof. i cof. Q fin. r) + 2 fin. t fin. V 

 j' = - X ( cof i fin. Q cof. r -f- cof g^ fin. r ) 



+ Y ( cof. i cof. ^ cof. r — fin. ^ fin. r ) -t- Z fin. i cof. r 

 g; — X fin. i fin. ^ — Y fin. i cof. ^-\-Z cof. i. 



§. 3. Praeterea vero etiam necefle eft vt coordi- 

 natae X, Y, Z etiam per noftras quantirates exiguas x, 

 jf, z exprimantur, quem in finem primo habebimus 



X'' r= ( I H- Jc) cof r —y fin. r , 



Y" =: ( I -f- jr) fin. r -^-j cof. r et Z" — z. 

 Deinde ex paragr. 1°. colligimus 



Y" cof. . - Z" fin. i — - X fin. ^ -h Y cof. ^ 

 Cum igitur fit X" zz: X cof ^ -f- Y fin. ^ erit 



X" cof. ^ - Y" cof. i fin. ^ -\- Z" fin. 1 cof. Q — X 



Porro 



X" fin. Q -H Y" cof i cof ^ - Z" fin. i cof. ^z^Y 



Denique Y" fin. i -\- Z" cof. i ~ Z. Quare fi hic valores an- 

 te inuenti fubftituantur, reperietur: 

 X :== (i + •X-) (cof r cof. ^ — cof i fin. r fin. ^) 



— ^(fin.rcof ^ + cof. icof. rfin.^ +2fin.i fin.^ 



Y — ( I H- -v) (cof. r fin. Q + cof. i fin. r cof. ^) 



— j ( fin. r fin. ^ - coY. i cof r cof ^ ) — 2; fin. i cof. ^ 



2 — ( I -f- .*■ ) fin. i fin. r -\-y fin. i cof r -\- z cof. i. 

 * 



§. 4. Quo has formulas fimpliciores rcddamus po- 



namus breuitaiis gratia: 



cof r cof ^ - cof » fin. r f n. ^ — w 

 cof r fin. ^ -h cof i fin. r cof. S^ = « 

 fin. r fin. ^ — cof i cof. r cof ^ = jx 

 fin. r cof ^ -}- cof. i cof. r fin. ^ — v 



qui- 



