MORTON—- ON THE PITCH LAKE OF TRINIDAD. 67 



of this spring and obtain a specimen, care being taken not to burn 

 the fingers. 



The surface of the lake is intersected by little canals, particu- 

 larly on the western side. Some of these are shallow and narrow, 

 others are three or four yards wide and from three to five feet deep. 

 The edges of these canals are rounded like the lips of an ancient 

 urn. And they seem to have been formed by the pitch, which had 

 boiled over from different springs, having met and cooled. Where 

 the springs have been near each other the overflowings have run 

 together, so that their meeting can scarcely be traced. But where 

 they have been more distant the pitch waves have had time to cool 

 somewhat before meeting, and thus hardened have met at the bottom 

 without running into each other, and the interval between their 

 edges forms a deep canal, wide at the surface and rounding down to 

 a crack at the bottom, where the overflowings have met. Lips 

 more or less gently closed may serve to illustrate the shape and 

 varieties of these canals. They are always full of water. We 

 enjoyed a tepid bath in some of the deepest and found them of the 

 same shape as the others. None of these canals intersect each 

 other; but where overflowings from three different springs have 

 met, three canals are formed, deepening in their course until they 

 converge into a deep triangular poo] . The pitch does not always 

 boil at the same part of the lake, nor always with the same activity. 

 And these overflowings' point to a time when the pitch springs have 

 been near the western side of the lake, and perhaps more than one 

 of them active at the same time. 



The western side has a shore or border of pitch, sloping more 

 or less gently towards the lake, indicating a depression in its level. 

 The eastern side presents a different appearance. Here the soil 

 covered with grass and bushes comes close to the lake. The lake 

 itself is smooth, and the canals on its surface few and small, indicat- 

 ing a greater internal heat. At the edge of the lake the soil is only 

 a few inches deep, and the land is very level, and seems really a 

 continuation of the lake with a superjacent shallow layer of earth. 

 This is conflrmed by appearances further inland, where the forma- 

 tion can be traced for about six miles. If, as we conjecture, the 

 land here rests, for some little distance, upon the pitch in a soft 

 and but little inspissated condition, it is easily seen that on a subsi- 



