Often wisps of smoke would trail from the moving embankments. Once cracks in the surface below Culebra issued boiling water. When Gaillard arrived to investigate the matter, he took a Manila envelope from his pocket and held it over one of the vents in the earth. In seconds the paper was reduced to ashes. The explanation, according to the geologist who was summoned, was “oxidation of pyrite,” but the terrified workers were convinced that they were cutting into the side of a volcano.
