GALILEO AND HIS JUDGES. 145 



ancients ever appears to have suggested the inter- 

 mediate theory of the Earth revolving on its axis, 

 and yet remaining stationary as regards any motion 

 of translation. With our present knowledge of 

 astronomy we could not entertain such an opinion, 

 though in the early part of the seventeenth century 

 it might have been considered plausible. Since, 

 however, it has not been maintained by any note- 

 worthy author, we need not further discuss it. 



The reader will bear in mind what has already been 

 said on this branch of the subject in the second day's 

 dialogue,* and it is not necessary to repeat it in 

 detail. It may, however, be useful to mention a 

 few experiments of a later date, which have tended 



* I may, perhaps, be permitted to recall to the reader's mind, 

 in a note, one or two of the main objections urged by the anti- 

 Copernicans. One of these was that it would leave the atmosphere 

 behind, the true answer to which is that the atmosphere itself is 

 attracted by the force of gravity to the earth, and is carried round 

 by the rotation, as everything else is ; this Galileo did not perfectly 

 understand, as may be seen by his remarks, both in the second 

 and the fourth day's dialogue. Another was this and it was put 

 forward by no less a man than Tycho Brahe a stone dropped 

 from a high tower ought to fall to the westward of the tower, 

 because the tower would be carried on to the east by the earth's 

 rotation, and the stone would not; this, however, being contrary 

 to experience. The real fact is that the stone partakes of the 

 rotatory movement as much as the tower does, the two forces of 

 rotation and gravity being combined according to the second law 

 of motion, while the stone is falling ; this Galileo did know. 

 Supposing a very high tower, the stone ought to fall slightly to the 

 east, on account of the superior velocity of rotation at the top of 

 the tower to that at the bottom. It is said this experiment has 

 been successfully tried, as stated in note, page 55. 



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