Stone Roads. 461 



the material taken from ditches on either side made for 

 drainage, building the earth or gravel nad upon this after 

 it has first been well spread and firmed. 



STONE ROADS. 



Stone roads of one form or another date back to and pos- 

 sibly beyond Roman times; and Fig. 217 represents two 

 types of the extremely massive and substantial roads 

 which were built ten or fifteen centuries ago, some of 

 which still survive. These roads had a width of 30 feet 

 and pavements of heavy stone at the bottom and often one 

 or more layers of stone bedded in cement to make the road 

 water proof. One type of construction which they fol- 

 lowed made the road consist of four lavers : 



FIG. 217. Two types of Ancient Roman stone roads. (After Shaler.) 



1. Two or three courses of flat stone or, if these were not 

 obtainable, of other stone, generally laid in mortar. 



2. A layer of rubble masonry or coarse concrete. 



3. A finer concrete upon which was laid 



4. A layer of paving blocks jointed with the greatest 

 nicety. 



It^is stated that with many of the great roads the paved 

 portion had a width of 10 feet bordered by raised stone 



