10 De successiva mutatione 



Quare fi pro pun&o fublimi Z temas coordinatas vo- 

 ce m us 



ax = X; xr=Yi & rz = z 



habebimus 



X=AT—R V=vcof.icof.\ — vfin. £ cof a fin.\; 



Y= TR ■+- V Y — v cof. £ fin. 4- -v- v fin. %cof.acof.-\,i 



& Z = V_/?/Z. |j?/2. ». 



XII. 



Ex his denique etiam definitur diftantia planeta- 

 rum Q_Z qux brevitatis gratia ftatuatur 



<2Z=r. 



Cum enim fit 



PX=AP — AX=ucof.Q — X, & 



P Q — XY—ufinA—Y, eric 

 QY'-=uu — 2u (Xcof. -*- Yfin. Q)+XX+YY; 

 cui quadratum YZ X —Z* additum dabit 



QZ* = t*= u u— i u (Xcof.Q-h Y fin. 0) 

 + XX+YY+Z Z. 

 At eft ^TX+ YY+ Z Z = vv, ideoque 



t- = U U 2 U ( J(f co/^ ■+- Y fin. 9 ) -4- V V. 



Verum ob cof, cof. 4 -*-jfo. 97?/?. 4> = co/^ (0 — 4) » & 



y?/2. 8 c<?/ 4* — co f §fin. 4 =fin. (0 — 4) ' 

 ubi notetur — ^ = £ A Q — E A Q exprimere an- 

 gulum ^ y4 Q , feu longitudiaem pianette Q a linea 

 nodorum fumcani. 



