xvi Contents 



PAGE 



89-90. Detailed theory of the planets : defects of the 



theory 121 



91. Coppernicus's use of epicycles 122 



92. A difficulty in his system . . . . . . 123 



CHAPTER V. 



THE RECEPTION OF THE COPPERNICAN THEORY AND THE 

 PROGRESS OF OBSERVATION (FROM ABOUT 1543 A.D. 



TO ABOUT I60I A.D.), 93~II2. . . . I2J-I44 



93~4- The first reception of the De Revolutionibus : 



Reinhold : the Prussian Tables . . . .125 

 95. Coppernicanism in England : Field, Records, Digges 127 

 96. Difficulties in the Coppernican system : the need for 



progress in dynamics and for fresh observations 127 

 97-8- The Cassel Observatory : the Landgrave William 

 IV., Rothmann, and Burgi: the star catalogue : 

 Biirgi's invention of the pendulum clock . .128 



99. Tycho Brahe : his early life 130 



100. The new star of 1572 : travels in Germany . 131 



101-2. His establishment in Hveen : Uraniborg and 



Stjerneborg : life and work in Hveen . .132 

 103. The comet of 1577, and others . . . .135 

 104. Books on the new star and on the comet of 1577 136 



105. Tycho's system of the world : quarrel with 



Reymers Bar 136 



106. Last years at Hveen : breach with the King . 138 



107. Publication of the Astronomiae Instauratae 



Mechanica and of the star catalogue : in- 

 vitation from the Emperor . . . .139 

 108. Life at Benatek : co-operation of Kepler : death 140 



109. Fate of Tycho's instruments and observations . 141 



1 10. Estimate of Tycho's work : the accuracy of his 

 observations : improvements in the art of 



observing */ 141 



III. Improved values of astronomical constants'. 



Theory of the moon : the variation and the 



annual equation 143 



112. The star catalogue: rejection of trepidation: 



unfinished work on the planets . , . 144 



