John Galt 
Life of Lord Byron [EPUB ebook] 

Excerpt: "The Acheron, which they crossed in this route, is now called the Kalamas, a considerable stream, as large as the Avon at Bath but towards the evening they had some cause to think the Acheron had not lost all its original horror; for a dreadful thunderstorm came on, accompanied with deluges of rain, which more than once nearly carried away their luggage and horses. Byron himself does not notice this incident in Childe Harold, nor even the adventure more terrific which he met with alone in similar circumstances on the night before their arrival at Zitza, when his guides lost their way in the defiles of the mountains–adventures sufficiently disagreeable in the advent, but full of poesy in the remembrance."