TRINIDAD.. 61 



curiosities in the world. The basin, which occupies rather more than 100 acres on 

 a slight rising ground about 85 feet above sea-level, usually presents the aspect of 

 an exposed coalpit ; but during the great heats the surface liquefies to a depth 

 of about an inch. Even before the contents began to be worked for industrial 

 purposes, the surface underwent frequent modifications ; islands were formed 

 and rapidly covered with agaves, wild pineapples and other vegetable growths ; 

 then they were swallowed up by the surging flood of pitch, to reajjjjear on the 

 circumference of some sluggish eddy in the viscous substance. 



The underground forces acting on the asphalt cause it to rise in masses of 

 imequal size, rounded off like huge toadstools and separated by narrow spaces 

 filled with water at the normal temperature of the surrounding atmosphere, 

 in which fishes disport themselves. The visitor may walk without any risk 

 on the solid asphalt round the margin of these channels, although, according 

 to the report of numerous travellers, the surface yields gently under the 

 weight. 



Towards the centre of the lake the bituminous substance is continually rising, 

 mixed with sulphurous gases, and it often ejects logs of wood, branches or stems 

 comjDletely transformed by the saturating matter. The wood thus cast up always 

 presents its pointed end to the air, so as at times to resemble rows of stakes. 

 The pitch, which is very impure and consequently of small commercial value, 

 contains from about one-fifth to cne-third. of earthy matter. The 78,000 tons 

 exported in 1890 were valued at a little over £90,000. 



The soil of the cultivated district encircling the lake is also charged with 

 asphalt, yet is extremely fertile, yielding the best and finest fruits in the island. 

 The pineapples especially are less fibrous, larger, more fragrant, and of a more 

 golden colour than elsewhere. The very road leading from the lake to the 

 neighbouring port of La Brea runs through a bed of pitch, and moves slowly 

 seawards like a black glacier. The little houses erected along the track 

 follow the same onward movement, so that they have to be periodically rebuilt. 

 The shore also is fringed with bituminous reefs, and some 800 yards south 

 of the headland a yawning chasm in the bed of the sea occasionally dis- 

 charges boiling masses of petroleum, which rises and spreads out on the surface 

 of the water. 



Under about the same latitude, but in Mayaro Bay on the east side of the island, 

 there occurs another submarine vent, whose eruptions, according to native report, 

 take, place with a certain regularity in the months of March and June every year, 

 and are accompanied by a roar as of thunder, and apparently also by " flames." 

 It is at all events certain that on these occasions the sea casts ashore lumps of 

 hard, black and shining asphalt, which is collected by the inhabitants of the 

 district. So long ago as 1805 it was manufactured by the English into a tar 

 used for caulking purposes. According to Wall and Sawkins, the geologists who 

 have most carefully studied this region, the asphalts both of the island and of the 

 neighbouring mainland are derived from v^egetable remains which, under temperate 

 and polar climates, would assume the forms of turf and lignite. 



