Some of the rivers flowing into Lake Valencia come from thermal springs, worthy of special note. These springs gush out at three points from the coastal granitic chain at Onoto, Mariara and Las Trincheras. I was only able to carefully examine the physical and geological relations of the thermal waters of Mariara and Las Trincheras. All the springs contain small amounts of sulphuretted hydrogen gas. The stink of rotten eggs, typical of this gas, could only be smelled very close to the spring. In one of the puddles, which had a temperature of 56.2°C, bubbles burst up at regular intervals of two to three minutes. I was not able to ignite the gas, not even the small amounts in the bubbles as they burst on the warm surface of the water, nor after collecting it in a bottle, despite feeling nausea caused more by the heat than by the gas. The water, when cold, is tasteless and quite drinkable.

We saw the Indians dancing. These dances are all the more monotonous as women do not dare take part. The men, both young and old, hold hands, form a circle, and for hours turn around to the right, then the left, in utter silence. Usually the dancers themselves are the musicians. Weak notes blown from reeds of different sizes make it all seem slow and sad. To mark the time the leading dancer bends both knees rhythmically. The reeds are tied together in rows. We were surprised to see how quickly young Indians could cut reeds and tune them as flutes when they found them on the banks.