xviii Contents 



PAGE 



130. Dynamical arguments in favour of the motion of 



the earth : the First Law of Motion. The tides 1 65 



131. The trial and condemnation. The thinly veiled 

 Coppernicanism of the Dialogue : the re- 

 markable preface 168 



132. Summons to Rome : trial by the Inquisition : 



condemnation, abjuration, and punishment : 

 prohibition of the Dialogue . . . .169 



133. Last years: life at Arcetri: libration of the moon : 

 the Two New Sciences : uniform acceleration, and 

 the first law of motion. Blindness and death . 172 



134. Estimate of Galilei's work : his scientific method . 176 



CHAPTER VII. 



KEPLER (FROM 1571 A.D. TO 1630 A.D.), 135-151 . 179-197 

 135. Early life and theological studies . . . -179 

 136. Lectureship on mathematics at Gratz: astronomical 

 studies and speculations : the Mysterium Cosmo- 

 graphicum . . . . . . . .180 



137. Religious troubles in Styria : work with Tycho . 181 

 138. Appointment by the Emperor Rudolph as successor 

 to Tycho : writings on the new star of 1604 and 

 on Optics : theory of refraction and a new form 



of telescope 182 



139. Study of the motion of Mars : unsuccessful attempts 



to explain it 183 



140-1. The ellipse: discovery of the first two of Kepler's 

 Laws for the case of Mars : the Commentaries 



on Mars 184 



142. Suggested extension of Kepler's Laws to the other 



planets 186 



6 143. Abdication and death of Rudolph : appointment at 



Linz 188 



144. The Harmony of the World: discovery of Kepler's 



Third Law : the " music of the spheres " . .188 

 145. Epitome of the Copernican Astronomy : its pro- 

 hibition : fanciful correction of the distance of 

 the sun : observation of the sun's corona . . 191 

 146. Treatise on Comets . . . . . . .193 



147. Religious troubles at Linz : removal to Ulm . . 194 



