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POPULAR SCIENCE MONTHLY. 



Good roadways are cheap at any cost, and bad ones are so disas- 

 trously expensive that only a very rich country, like the United 

 States, can afford them." 



Space will not permit even a brief history of street paving, or 

 an attempt to sketch its development, but reference will be made 



to the different kinds 

 in general use, and the 

 kind most in favor in 

 various cities. Prob- 

 ably no one has intro- 

 duced the subject of 

 pavements without ref- 

 erence to the Roman 

 roads. 



While Carthage was 

 probably the first city 

 to boast of paved 

 streets, the Romans 

 soon followed its exam- 

 l)le, and all over Eu- 

 rope, Asia, and Africa, 

 as far as the domain 

 of their emperors ex- 

 tended, they built with the greatest care and at enormous expense 

 that magnificent system of roads which were often supposed, in the 

 middle ages, to be of supernatural origin, and remain the w'onder of 

 our modern civilization. These roads were generally from four 

 to six metres in width, and were constructed in this way: The road- 

 bed was excavated; in it was placed a layer of stones, which were 

 sometimes united wdth mortar. These stones were such as were 

 most available, sometimes rounded stones similar to the cobble- 

 stones with wdiicli we are familiar, and in some cases in the Alps 

 the foundation was a compact mass of angular stones, two feet or 

 more in tlicir longest dimension, carefully fitted together. 



On this foundation was placed a layer of plaster made of stone 

 or brick pounded with mortar; then a course of sand and lime or 

 sand and clay, leveled and pounded until very hard. The top or 

 wearing surface was made of irregular flat stones, fitted together 

 with nicety and united with cement. The total depth of these 

 roads, or pavements, as they can properly be called, was from three 

 to (in some cases) seven feet. It is said that in the province of 

 Hispania alone (Spain and Portugal) twenty thousand miles of 

 roads were built. 



The first stone pavements to be laid in modern city streets were 



A Strekt in Pompeii, showing Old Koman Pavement. 



