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POPULAR SCIENCE MONTHLY. 



In Utah, upon the Uintah Indian reservation, are found veins of 

 asphaltum of remarkable purity, to which the name 'Gilsonite' has been 

 given. It has been found very useful for insulation and a great variety 

 of purposes, but has only been used in combination with softer material 

 for paving. 



Among the coast ranges of California there are deposits of asphal- 

 tum and siliceous asphalte of vast extent. At Santa Cruz, to the east 

 and west of Santa Barbara, near the coast near San Buena Ventura and 

 Los Angeles, on the Ojai ranch, and at Asphalto, in Kern County, the 

 principal ones are found. Those of commercial value are at the works 

 of the Alcatraz Company, west of Santa Barbara, and near Asphalto. 

 At the works of the Alcatraz Company the bitumen is dissolved in a 



Fig. 8. Asphaltum Glacier, Kern County, Cai 



solvent and conveyed through pipes some thirty miles to the coast, 

 where the solvent is removed and the bitumen prepared for shipment. 



At Asphalto, on the north side of the Coast range, in Kern County, 

 the asphaltum occurs nearly pure in veins of great extent that have been 

 mined to a depth of more than three hundred feet. From these state- 

 ments it will be seen that the deposits of asphaltum and asphalte in 

 the United States are of vast extent and variety. 



While the bitumen in these different deposits in different parts of 

 the world bears a generic relation, there are specific differences between 

 the different varieties that render some of them more desirable for cer- 

 tain purposes than the others. The purest asphaltums are brilliant 

 black, brittle solids that consist of compounds of carbon and hydrogen 

 with small proportions of oxygen, sulphur and nitrogen. The latter 



