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POPULAR SCIENCE MONTHLY. 



While it might be interesting to describe in detail all the minerals 

 mentioned in this table, we are at present concerned with only two, viz., 

 asphaltums and asphaltes. Again, while it might be interesting to 

 describe asphaltums and asphaltes from all the many localities in which 

 they occur, we are at present concerned only with those in use in street 

 paving, and particularly those in use in the United States. 



It is said that the idea of constructing a roadway of asphalte was 

 first suggested by the observation that lumps of asphalte that have 

 dropped from carts upon a road, when trodden by animals and rolled 

 beneath wheels, became compacted into a homogeneous and resisting 

 surface. These observations were made in eastern France, in the valley 

 of the Rhone, where very extensive deposits occur, extending into 

 Switzerland. They were first brought into notice, about 1721, by Eirinis 



Fig. 1. The Pitch Lake in Trinidad as it Appeared Before 1890. 



d'Erynys, a Greek physician, who published a pamphlet in which were 

 described deposits of sand and limestone saturated with bitumen that 

 he had discovered some years previously in the Val de Travers, Canton 

 of Neufchatel, Switzerland. He described also a bituminous distillate 

 which he used in the treatment of disease. He compared the deposits 

 to similar beds in the valley of Siddim, near Babylon. They were for- 

 gotten for nearly a century and then re-discovered. 



By whom this material was first used in road building is unknown. 

 Early in 1850, M. de Coulaine published a paper in the "Annales des 

 Ponts et Chausses/ in which he discussed the use of bitumen in road 

 building as if it was an established industry. He states, without giving 

 any date, that the first attempt to construct a street of bitumen in Paris 

 was made upon the Place Louis XV., opposite the Church of Saint 



