Page:Popular Science Monthly Volume 61.djvu/222

216 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

asphalt-surfaced street were forced to use such materials as were available. 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