Newton occupied in grinding hyperbolical Lenses — H is first Experiments with the Prism made in 1666 — He discovers the Composition of White Light, and the different Refrangi bility of the Rays which compose it — Abandons his attempts to improve Refracting Telescopes, and resolves to attempt the Construction of Re?ecting ones — He guits Cambridge on Account of the Plague Constructs two Re?ecting Telescopes in 1668, the first ever executed — One of them examined by the Royal Society, and shown to the King — He constructs a Telescope with Glass Specular — Recent History of the Re?ecting Telescope Airy's Glass Specula Hadley's Re?ecting 7 elescopes Short's Herschel's Supposed Decline of Science in England.