461 



NOTES TO BOOK V. 



(p.) p. 403. THE doctrine of the motion of the 

 earth was first publicly maintained at Rome by Wil- 

 manstadt, who professed to have received it from Co- 

 pernicus. See Venturi, Essai sur les Outrages Physico- 

 Mathematiques de Leonard da Vinci, awe des Fragmens 

 tires de ses Manuscrits apportes d'ltalie. Paris, 1797 : 

 and, as there quoted, Marini Arcliiatri Pontificii, Tom. n. 

 p. 251. 



Leonardo da Vinci himself, about 1510, explained 

 how a body by describing a kind of spiral, might de- 

 scend towards a revolving globe, so that its apparent 

 motion relative to a point in the surface of the globe, 

 might be in a straight line leading to the center. He 

 thus showed that he had entertained in his thoughts 

 the hypothesis of the eartfr's rotation, and was employed 

 in removing the difficulties which accompanied this sup- 

 position, by means of the consideration of the composition 

 of motions. 



Regiomontanus (who died in 1476) is said to have 

 been inclined to this hypothesis, but to have combated 

 it ex professo : \ 



(Q.) p. 418. It appears to me that the different de- 

 gree of toleration accorded to the heliocentric theory in 

 the time of Copernicus and of Galileo, must be ascribed 

 in a great measure to the controversies and alarms which 

 had in the mean time arisen out of the Reformation in 



5 Schoneri Opera, Part n. Art. 127. 



