122 CONVERSATIONS ON 



top of houses, and streets run over streets, 

 until they leach up as high as two-thirds of 

 the ins'.de wall. But under the top of their 

 outside case they always leave a large open 

 place that is never filled up with houses. And 

 around this space they will build three or four 

 large arches, sometimes two or three feet high ; 

 these I suppose are to prevent the houses from 

 falling in towards the centre of the city, which 

 is* an open space, and on the other side they 

 are fastened to the outside walls, so that these 

 houses are very firm." 



"And what is all this made of, Uncle 

 Philip?" 



" All of clay, except the nurseries, which I 

 told you were made of wood and gum. Over 

 the house of the king and queen there is a 

 sort of flat floor, some distance above it, with 

 nurseries and magazines between the under 

 side of it and the top of the queen's house. 

 This floor will not let the water through it, 

 so as to wet tlus palace where the king and 

 queen live, but will turn it off into large 

 trenches or gutters under ground, of which 

 I will speak directly. The bridge I told you 

 of they build from this floor in the open 

 space, directly under the top or dome of the 



