CHAPTER VIII.. From Galilei to Newton (from About 1638 a.d. to

FROM GALILEI TO NEWTON (FROM ABOUT 1638 A.D. TO ABOUT 1687 A.D.), §§ 152-163 198-209

§ 152. The general character of astronomical progress during the period 198

§ 153. Scheiner’s observations of faculae on the sun. Hevel: his Selenographia and his writings on comets: his star catalogue. Riccioli’s New Almagest 198

§ 154. Planetary observations; Huygens’s discovery of a satellite of Saturn and of its ring 199

§ 155. Gascoigne’s and Auzout’s invention of the micrometer: Picard’s telescopic “sights” 202

§ 156. Horrocks: extension of Kepler’s theory to the moon: observation of a transit of Venus 202

§§ 157-8. Huygens’s rediscovery of the pendulum clock: his theory of circular motion 203

§ 159. Measurements of the earth by Snell, Norwood, and Picard 204

§ 160. The Paris Observatory: Domenico Cassini: his discoveries of four new satellites of Saturn: his other work 204

§ 161. Richer’s expedition to Cayenne: pendulum observations: observations of Mars in opposition: horizontal parallax: annual or stellar parallax 205

§ 162. Roemer and the velocity of light 208

§ 163. Descartes 208