A SOLID FIRMAMENT' 287 



XIV 



STILL, I will descend to the task. Let the man i 

 who has placed such a solid roof on the world tell 

 me what reason there is for believing his statement 

 that the heavens have such a thickness. What was 

 it that took all these solid bodies up there and kept 

 them there ? Then, a firmament of such thickness 

 must necessarily be of immense weight too. How 

 is it that heavy bodies remain aloft? How is it 

 that the huge mass does not come down and smash 

 itself by its own weight? It is, I imagine, a 2 

 physical impossibility that such a vast weight as 

 Artemidorus has brought to the support of the 

 heavens should hang suspended, or be supported by 

 a slight foundation. Nor can it be alleged that 

 there are stays l of some kind outside by which it 

 is prevented from falling. Nor again can there be 

 any support in the centre 2 to receive and prop up 

 the threatening mass. And again, no one will 

 venture to assert that the universe is being con- 

 stantly carried down through the immensities of 

 space, falling all the time, though it is not evident 

 that it falls, because its headlong course is to all 

 eternity, having no final obstacle with which to 

 collide. This is indeed a statement people have 3 

 made about the earth, when they could discover no 

 explanation for a mass standing poised in air. It is 

 borne down, say they, for ever ; but it is not evident 

 that it falls because the space into which it falls is 

 endless. 



1 The word is usually applied to a flexible fastening, hawser, cable, or the 

 like. 



2 Or, between the earth and it. 



