TRINIDAD AND BERMUDEZ ASPHALTS 



i73 



exudes and some gas cavities are found in the general mass of the pitch 

 beneath the crust. As the asphalt below the crust of the deposit is the 

 only portion of value for paving, the question has arisen as to its 

 uniformity. 



An examination of a series of samples collected in 1894 shows that the 

 asphalt from the Bermudez deposit may vary very largely in the amount 

 of water which it contains, from 11 to 46 per cent. None of it, however, 

 is present in the form in which it occurs in Trinidad asphalt. It is not 

 emulsified with the bitumen, but is all adventitious surface water. The 

 percentage of oils which it volatilizes at about 400° F. varies from 16 

 to 6 per cent., consequently the consistency is far from uniform. The 

 material carefully selected for use industrially is fairly constant in 

 character, however, and when carefully refined has the following 

 proximate composition : 



The Composition of Kefined Bermudez Asphalt 



Specific gravity, 77/77° F., orig. substance dry 1.082 



Color of ponder or streak Black 



Luster Bright 



Structure Uniform 



Fracture Semi-eonchoidal 



Hardness — original substance — at 77° F Soft 



Odor Individually asphaltic 



. 



MrU 



w 



:\ 



■ ■■■•■ vy 



V 



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Photo, W. H. Rau, Philadelphia. 

 Dump of Crude Bermudez Asphalt at Guanaco. 



