3 o PHYSICAL SCIENCE BK. i 



6 ful than they are in reality. The stars appear 

 bigger if seen through a cloud, because our vision 

 is blurred in the moisture, and cannot accurately 

 grasp its object. This will become plain to demon 

 stration if you fill a cup with water and throw a 

 ring into it. While the ring lies right at the bottom 

 its appearance is visible on the surface of the 



7 water. Anything, in fact, that is seen through 

 moisture appears far larger than in reality it is. 

 What wonder that the image of the sun, being 

 seen in a moist cloud, should be reproduced on a 

 scale larger than the original, and that for the two 

 reasons indicated ? The cloud contains the two 

 elements, one like glass, which can transmit light, 

 and one also of the character of water ; at any rate, 

 if it does not just yet contain the actual water, it 

 is now forming it, its nature is already such as can 

 easily be changed into water. 



VII 



1 As you have mentioned glass, some one inter 

 poses, I can draw from this same material an 

 argument to confute you. Glass sticks are manu 

 factured, either fluted or bulging, 1 with many 

 corners like a club. If one of these sticks is placed 

 obliquely in the path of the sun s rays, it sends 

 back the colour which is wont to be seen in the 

 rainbow. This proves that there is not here an 

 image of the sun, but an imitation of his colour 



2 from reflection. Now, in this argument there are 

 many points that make for my view. First of all, 

 it is plain that there must be some smooth surface 

 like a mirror to reflect the sun. Secondly, it is 



1 Another reading gives &quot; twisted.&quot; 



