THE KING'S MIRROR 13 



that the inhabited part of the earth is an island floating 

 upon the waters of the great Ocean, by which it is also 

 surrounded. This belief was generally maintained in 

 the earlier centuries of the classical world, and it had 

 wide acceptance in the middle ages.' There were also 

 those who held that beyond and around the outer Ocean 

 is a great girdle of fire. It is likely, however, that many 

 believed with Isidore of Seville that it is useless to spec- 

 ulate on subjects of this sort. ' Whether it [the earth] 

 is supported by the density of the air, or whether it is 

 spread out upon the waters ... or how the yielding air 

 can support such a vast mass as the earth, whether such 

 an immense weight can be upheld by the waters without 

 being submerged, or how the earth maintains its balance 

 . . . these matters it is not permitted any mortal to 

 know and they are not for us to discuss." * 



There can be no doubt that the author of tl\e KinQ 9 

 Mirror believed in the Ptolemaic theory of a spherical 

 n speaking of our planet he uses the term jar- 

 J( earth-sphere. In an effort to explain why some 

 countries are hotter than others, he suggests an experi- 

 ment with an apple. It is not clear how this can shed 

 much light on the problem, but the author boldly states 

 the point to be illustrated: " From this you may infer 

 that the earth-circle is round like a ball." J 



Toward the close of the medieval period there were 

 certain thinkers who attempted to reconcile the spheri- 

 cal theory with the belief that the inhabited part of the 

 earth is an island. These appear to have believed that 



* De Natura Rerum Liber, c. xlv: Migne, Palrologia Latina, LXXXIII, 1015. 

 t See c. xix. J See c. vii. 



