2l6 



POPULAR SCIENCE MONTHLY 



The great popularity of these streets in Europe led to attempts to 

 construct similar streets in the United States. This was at first a 

 difficult problem as at that time no bituminous limestone was known in 

 America, and those who attempted to introduce an imitation of an 



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asphalt-surfaced street were forced to use such materials as were avail- 

 able. A number of streets were laid in Washington, D. C, of a sort 

 of bituminous concrete, made of coal tar pitch and broken stone that 

 was laid very thick. Some of these streets are now in existence, more 



