i8o 



THE POPULAR SCIENCE MONTHLY 



Agitation is provided by passing some of the live steam through the 

 crude material while it is heating. When there is no further evolution 

 of steam and the melted mass has become tranquil, it is drawn off from 

 the bottom of the tanks into open cement barrels placed on flat cars. 

 These are not filled at once, but are topped off after the first filling has 

 cooled, so that there shall be no loss of material. The product obtained 

 in this way is the refined asphalt of commerce, and is in shape for ship- 

 ment to whatever point there may be demand for it. 



It may be interesting to note that the amount of crude material 

 shipped from Trinidad during recent years, has reached as high as 180,- 



Fifth Avenue at 34th St., New York City. Paved with Trinidad Asphalt 1897, 



photographed 1911. 



000 tons per year, while that from the Bermudez deposits has reached 

 as high as 47,000 tons but is rapidly increasing. The entire amount 

 shipped from Trinidad since 1867 has reached three million tons, which 

 would be equivalent to 180 million square yards of sheet asphalt 

 pavement. 



Service Tests of Trinidad Asphalt 



Trinidad asphalt being for many years the only available supply of 

 such material, it was the only one used in the early days of asphaltic 

 highway construction in the United States. It has been subjected to 

 the most varied environment with the most satisfactory results. There 

 are in existence to-day three pavements which are worthy of considera- 

 tion, as showing its capacity to meet different kinds of traffic and dif- 

 ferent climatic conditions. 



