Ofoscoia . 
L E M M 
FOrmulse differentialis "^*^' - invenire fummatoriam trado- 
ria defcripta . 
Defcripta traaoria KM, {'Big» i) ciijus ordiRata pri- 
ma fit CK — fuper qua dekripto conjugato ciiculi qua- 
drante KFG, abfcinde CH = ^, & duc HF, FM, qua- 
rum altera perpendieularis fit , altera parallela allyrrptotoi 
denique ex pundo M duc tangentem MT: ajo FM, vei 
CT pfopofitam formulam integrare , 
Demonjlratio » Abfci fTa m , ordinataraque tra<florix eifdem 
fymbolis exprimo , quibus antea ufus fum i igitur H N 
^s-^x — s-hS — i~ \/ a a — yj\ fed aa~yy~ss, ex 
qua fit =^ = : Igitur H N = / + S . Sumptis 
itaque differentiis fiet differentia HN=V>f-f- = 
fed HN^FM=CT. Igitur FM, feo GT = S-- 
Q. E. D. 
PROrOS IT 10 OCTAVA. 
a d e 
z % 
"D Edificare fyntradorias . 
^ Probkma hoc folvendum mihi propono in fyntrado- 
- riis inferis , quando , ur animadverfum eit in fuperiOMs co- 
rollario primo, inferis SEquales funt fuperae , dumrrodo or- 
dinata prima tradoris inter earum primas oidir.aras fit me- 
dia proportionalis arithmetica Inferss itaque red ficaris con- 
ftat etiam de fuperarum redificatione . Stt BD ('Btg> lo. 
II) fyntra^^oria re^lificanda , tradoria genirrix KM, MT 
tangens tradorix fecet fyntradoriam in D, & aflymptoron 
in T, R fit centrum ofculi trad^oriac , ex quo ducantur 
RM, RD, RTi arcus autem infinite parvi refpondenics 
fint Vim ^ D d , 
Quando ex fupcriore KM : KD : : M m : D d , fi orania 
Q,qq 2 ex- 
