In volume VIII of The History of Middle-earth, in chapter IV, The Second Map, is a list of the rivers of Gondor. Some of the rivers named in this list are followed by notes, which in some cases are clearly interpretations of the rivers' names (and in other cases clearly are not). Next to Poros is the word 'boundary', which appears to be meant as an interpretation of the name. This would certainly make sense, because the river marked the boundary between Gondor proper and Harondor to the south. Given the structure of the list, however, and the fact that many of its other names were later altered or abandoned, it's impossible to be sure whether Tolkien meant this as a final interpretation of the name Poros. |