TRINIDAD AXD BERMUDEZ ASPHALTS 171 



Photo. W. H. Rau, Philadelphia. 

 Bermudez Pitch Lake, Venezuela. 



while the deepest part of the soft maltha is only 9 feet and the average 

 of pitch below the soil and coke only 4 feet. At points there is not 

 more that 2 feet of pitch, and in the morichales or palm groves it is 

 often 5 feet below the surface. At several points scattered over the sur- 

 face are areas of soft pitch, or pitch that is just exuding from springs. 

 The largest area is about 7 acres in extent and of irregular shape. This 

 has little or no vegetation upon it, and from the constant evolution of 

 fresh pitch is somewhat raised above the level of the rest of the deposit. 

 This soft asphalt has become hardened at the edges, but when exposed 

 to the sun is too soft to walk upon. The material is of the nature of a 

 maltha and it is evidently the source of all the asphalt in the lake, from 

 these exudations the pitch having spread in every direction, so that no 

 great depth of pitch is found even at this point. 



A careful examination of the surroundings shows that in one 

 respect there is a resemblance between the point of evolution of the 

 soft pitch at the Bermudez and at the Trinidad lakes. Gas is given off 

 in considerable quantities at both places, and in both cases consists, 

 partly, at least, of hydrogen sulphide. 



The consistency of the soft pitch at the center of the Bermudez lake 

 is much thinner than that of the Trinidad lake. It will run like a 

 heavy tar and does not evolve gas in the same rapid way or harden as 

 quickly after collection. It therefore does not retain the gas which is 

 generated in it, nor does the deposit as a whole do so to the same extent 

 as the Trinidad pitch. 



