160 CORRESPONDANCE. 1687. 
DEF, EFG &c. dctinemo rt pren 
facilè patet, femper in pofterioribus 
contineri, quæ in prioribus. Si | 
in fig. 8. “fupponamus duo punéta | ! 
cidere, curva 7. fig. drinans 
in 7. fig. rurfus duo punéta co 
curva 6. Ne defcribetur ; fi 
_ fig. duo < ir 
(2e Extrait P. 71375) 
Tangentes ftatim ex ipfà defcriptione, fine ullius voit ne 
ufu, determinari. Quâ de re hæc pauca præcipere place. Sit 1 
quæ unicum habeat centrum: hoc five fit punétum A 
curva G in fig. 15. Si jam ad extremitates radiort 
fig. has curvas defcribentium, erigantur perpendi 
defcriptas tangent. Sint 2 curvæ ex duobus centris defc 
fint punéta, uti in f 
Fig. 16. ; curvæ, veluti in f 
. quæcunque & pu 
primitur: fi 
lineam Rad divifo, S _ 
