Another terrible scourge to the traveller in the Cordilleras is the _surumpe_, a violent inflammation of the eye, brought on by the sudden reflection of the sun from the snow. In those mountains the eyes are kept continually in an irritated state by the rarefied air and cutting winds, and are consequently unusually susceptible. Often the heavens become suddenly overcast, and in a few minutes the yellowish-green waste is one sheet of snow. Then out bursts the sun with overpowering splendour, a sharp burning pain is instantly felt in the eyes, and speedily increases to an unbearable extent. The eyes become red, the lids swell and bleed. So violent is the agony as to cause despair and delirium. Dr Tschudi compares it to the sensation occasioned by rubbing Spanish pepper or gunpowder into the eyes. Chronic inflammation, even total blindness, is the frequent consequence of the _surumpe_ in its most intense form. In the Cordilleras it is no unusual thing to find Indians sitting by the wayside, shrieking from pain, and unable to continue their journey. The Creoles, when they visit the mountains, protect themselves with green spectacles and veils. During five months of the year, from November till March, storms are of almost daily occurrence in the Cordilleras. They commence with remarkable punctuality between two and three in the afternoon, and continue till five or half-past; later than this, or in the night, a storm was never known to occur. They are accompanied by falls of snow, which last till after midnight. The morning sun dispels the cold mist that hangs about the mountain peaks, and in a few hours the snow is melted. "On the raging ocean," says Dr Tschudi, "and in the dark depths of the aboriginal forests, I have witnessed terrific storms, whose horrors were increased by surrounding gloom and imminent danger, but never did I feel anxiety and alarm as in Antaichahua, (a district of the Cordilleras celebrated for storms.) For hours together flash followed flash in uninterrupted succession, painting blood-red cataracts upon the naked precipices; the thunder crashed, the zigzag lightning ran along the ground, leaving long furrows in the scorched grass. The atmosphere quivered with the continuous roll of thunder, repeated a thousand-fold by the mountain echoes. The traveller, overtaken by these terrific tempests, leaves his trembling horse, and seeks shelter and refuge beneath some impending rock."