&66 DE MOTV TVRBINATORIO 



§. 31. Vt haec elementa facilius inueniri 

 queant , ftatuamus • 



d xzzp d z et dy zzq d z, eritque 

 duzzdzVpp-\-qq et dszzdzV i-\-pp-+-qq. 

 His pofitis in plano tabulae habebimus 



YT-2 ^pp-t-qq, 

 et cum fit tang. $ — *- , erit angulus elementaris 

 TYtzzd&zz i±L=pAji 



Pp-i-qq » 



vnde fit lineola 



T a — z ^ d P —-pdq) . 



V P P -t- q~q 

 Tum vero erit 



t uzz vi PjLt^-^Jtf • 



hincque colligitur fpatiolum 

 7 tzzz Vdp -\-dq\ 



Nunc quia triangulum T / u fimile eft triangulo 

 Y T S ob 



YT-2 Vpp-\- q q 

 reperietur perpendiculum 



V d p- -f- d g* * 



§.32. Nunc ad elementa extra planum tabu- 

 lae geminas flcftamus acies : et quia eft 



2 T — z V 1 -f- pp-\- ~q~q~ 9 



cius- 



