258 A HTLL-TOP STRONGHOLD. 



never gets in northern lands, but which remind one 

 so exactly of the painted background to a fifteenth- 

 century Italian picture that nature seems here, to our 

 topsy-turvy fancy, to be whimsically imitating an effect 

 from art. But in between those two tossed and tumbled 

 guardian ridges, the valley of the Arno, as it flows 

 towards Pisa, with the minor basins of its tributary 

 streams, expands for a while about Florence itself into 

 a broad and comparatively level plain. In a mountain 

 country so broken and heaved about as Peninsular 

 Italy, every spare inch of cultivable plain like that has 

 incalculable value. True, on the terraced slopes of the 

 hillsides generation after generation of ingenious men 

 have managed to build up, tier by tier, a wonderful 

 expanse of artificial tilth. But while oil and wine can 

 be produced upon the terraces, it is on the river valleys 

 alone that the early inhabitants had to depend for their 

 corn, their cheese, and their flesh-meat. Hence, in 

 primitive Italy and in primitive England alike, every 

 such open alluvial plain, fit for tilth or grazing, had 

 overhanging it a stockaded hill-fort, which grew with 

 time into a mediaeval town or a walled city. It is just 

 so that Caer Badon at Bath overhangs, with its prehistoric 

 earthworks, the plain of Avon on which Beau Nash's city 

 now spreads its streets, and it is just so that Old Sarum 

 in turn overhangs, with its regular Roman fosses anl 

 gigantic glacis, the dale of the namesake river in Wilts, 

 near its point of confluence with the stream of tha 

 Wily. 



