Bb MundiSystemate.

428 PHILOSOPHIA NATURALIS

PROPOSITIO XXXI. PROBLEMA XII.Invenire motum horarium Nodorum Lunas in Orbe Ellipticos

Designet G^pmaq Ellipsin, axe majore A?> minore ab de-scriptam, §1/4q Circulum circumscriptum, T Terram in utriusquecentro communi, S Solem, p Lunam in Ellipsi motam, &cpm ar-cum quem data temporis particula quam minima describit, N&nNodos linea Nn jundos, pK & m k perpendicula in axem de-missa & hinc inde produda, donec occurrant Circulo in T ik. M*

A.I a

& lineae Nodorum in O & d. Et si Luna, radio ad Terram duc-to , aream describat tempori proportionalem, erit motus Nodi inEllipsi ut area T

Nam si *P F tangat Circulum in T , & produda occurrat TJ*in Fy & pf tangat Ellipsin in p & produda occurrat eidem JF-