56 GALILEO AND HIS JUDGES. 



ever tried the experiment, which, of course, he had 

 not. He then tells him, and most truly so, that the 

 experiment, if made, would show a very different 

 result, and that the stone would fall at the foot of 

 the mast, whether the vessel were in motion or not. 

 Further on, Simplicio maintained that a projectile 

 thrown from the hand, according to Aristotle's 

 argument, is carried on by the air, itself set in 

 motion by the hand of the projector; and if the 

 stone let fall from the mast of a ship falls at the 

 foot of the mast, it must be the effect of the air. 

 So again he imagines that a ball dropped from the 

 hand of a man, riding fast on horseback, falls some 

 way behind, and does not partake of the horse's speed. 

 Salviati, however, tells him that he deceives himself, 

 and that experience would teach him the contrary. 



Various difficulties are discussed in this dialogue 

 well known to the disputants of that day. It being 

 questioned why a projectile shot from a gun point- 

 blank towards the east does not fall above the mark 

 aimed at ; or shot westwards fall below it ? How it 

 is that birds, when flying, are not left behind by the 

 revolving Earth, since they at any rate are completely 

 detached from the ground above which they are soaring? 

 Why it is that light objects do not fly off at a tangent? 



One sees throughout the power of the master-mind 

 of Galileo. He knew many things in mechanics 

 which no subsequent research or experiment has ever 

 corrected ; but here and there, as may naturally be 

 supposed, he is at fault. It must ever be remem- 



