The True Doctrine of Orbits: An Original Treatise on Central Forces

anomaly aphelion apse area described areas in equal astronomers attraction body moving central force centre of force centrifugal force centripetal force chord circular theory circumference comet conclusion constant curvature curve cycloid diameter diminished direction doctrine of orbits earth eccentric anomaly eccentric orbit ellipse elliptical theory epicycloid epitrochoid equal areas equation equiangular spiral finite focus force tending force varies formula given hence hyperbola hypocycloid increased infinite law of equal law of force law of gravitation limit major axis miles per hour moon moving body Newton Newton's demonstrations non-eccentric orbit observed orbital motion parabola perihelion distance perihelion velocity period perpendicular planet planetary position precipitation Prop proposition quadrature radius vector represents revolution revolve rolling circle square straight line subtense sun's Suppose supposition tangent Theorem theory of orbits tion triangle variable variation varies inversely whence