CHAPTER V. 



As a sequel to the story of Galileo, I think it may be 

 interesting to inquire what the evidence, as we now 

 have it, proves with regard to the truth of the Coper- 

 nican theory, there being two opposite and contra- 

 dictory errors on this subject, and these not merely 

 popular errors, but shared to some extent by educated 

 and otherwise learned men. But I must, before pro- 

 ceeding, remind my readers that I use the word 

 Copernican simply to signify the system of modern 

 astronomy, that in which the Sun is the centre round 

 which the Earth and the other planets revolve, and not 

 as meaning the precise theory of Copernicus, which 

 (as I have said) was overthrown by Kepler, when he 

 discovered that the planetary orbits were not circular 

 but elliptical, the Sun, moreover, not being strictly 

 in the centre, but in one of the foci of the orbit. 



Now it is a plain fact, which all persons must per- 

 ceive, that either the Earth revolves on its axis in 

 twenty-four hours (more accurately 23 hours 56 mins. 

 5 sees.), or else that the whole of the celestial bodies 

 are carried round the Earth in that same time. It is 

 also a fact no less perceptible to careful observers, 



