ee, 

 3. Paving Cement 



1894.] CRONISE PITCH LAKE OF TRINIDAD. 283 



The four conditions from the lake to the pavement are, approx- 

 imately, — 



„ , T.- t i 80 to Qo'i. asphaltum, 

 Crude Pitch, { \ r ■ 



20 to lofo foreign matter. 



Pitch Epuree, or refined asphaltum. 



\ 88ff asphaltum, 



[ i2</c petroleum residuum. 



I 12 to \6<fc paving cement, 



4. Asphaltic Pavement, \ 73 to 67^ clean sand, 



' 15 to 17^ pulverized carbonate of lime. 



This pavement, substantially so made, is the one now laid by 



most of the American asphalt paving companies, the Warren-Scharf 



Company and the Barber Company which work in most parts of the 



country, and the Rochester Vulcanite and other companies which 



operate locally in their several cities or sections. The pavement 



originally laid by the Rochester Vulcanite Company was a compound 



of Trinidad asphalt, sulphur, lime, cement, sand, stone dust and 



distillate of coal tar, but the pavement now laid by this company is 



substantially the same as that first described above. 



Trinidad Land Asphalt. 



Besides the " lake asphalt " from Trinidad the island furnishes 

 what is known as "land asphalt," referred to above. This is mined 

 in several places in the island, near LaBrea, and is estimated to cover 

 3,000 acres. Nearly all of this is covered with earth. Whether it is 

 an old overflow from the lake or comes from the rich bituminous 

 sandstone beneath is a much discussed question. It is harder and 

 contains more impurities or foreign matter than the lake pitch. 

 Even when refined it is said to be inferior to the lake product. 

 Pavements of this land asphalt were recently laid in Denver by the 

 West Indies Asphalt Company, now defunct, under the claim that it 

 was " Trinidad Asphalt " and complied with their contract. The 

 pavements were taken up within the year and the company compelled 

 to pay for repaving with lake asphalt. Those interested in the land 

 asphalt claim for it that it is from the same source and of the same 

 quality when refined as the lake asphalt. Large quantities of the 

 land asphalt are used, as the Trinidad Custom House receipts for the 

 March quarter of 1892 show an export of 10,233 tons, nearly all to 

 the United States, which would indicate about 40,000 tons a year. 

 The customs receipts for the same period indicate an export of lake 

 asphalt of about a hundred thousand tons a year. 



