Cylchgronau Cymru

basin. More would be found were the margin extended northwards. In Silvan Evans's list, which covers the whole of Montgomeryshire, three names appear twice, two three times and one four times. In the List below the following names appear more than once: Brwynen Camen Ceunant Cledan Colwyn Crygnant Dolau Gwynion Einion Eira Esgair Ewig Felen Ffinnant Ffridd Glyn Goch Gorlan Gwyllt/Wyllt Hafesp/Haffes Hely/Helygi/Luggy Hebog Hirnant Maesgwyn March/Marchnant Llwyd Pistyll Gwyn Rhaeadr Rhuddwr Sarn/Sarnau Sebon Tanat Twrch Wenallt Wern The duplication of names of the associative type, e.g. Glyn, Maesgwyn, has come about through association with places which happened to have had identical names These differ in their origin from names of the independent type, e.g. Hebog, Sebon, which arose through people having the same thoughts and feelings about two streams. It does not seem that duplication led to any confusion. Usually, but not always, (v. Sebon), streams with the same name were some distance apart and in a rural and fairly selfsufficient community the occasion for communication about streams outside the immediate neighbour- hood was infrequent. It is in recent times that the existence of the same name for different streams may have led a tourist astray or puzzled a bureaucrat in centralised administration. There is also another kind of duplication, the opposite of what has been discussed above. Some streams have more than one name for their whole or for part of their length. The details of the names by which Efyrnwy and Banw have been known over the centuries provide the best illustrations of this feature. It has been possible to follow the changes in the names of these two rivers because relatively ample documentation exists. Were this not so, the only names known today would have been Banw and Efyrnwy. It is reasonable to believe that for many streams which are not mentioned in charters and later documents other names were in use in the past. An extensive study such as this one of a specified area illustrates facts concerning stream- names which are well known to students but which are also of sufficient general interest to merit some discussion. The use of the same name for more than one stream, the existence of more than one name for the same stream, and the use of different names for different stretches have already been mentioned. The most important fact however is that very many streams over a period of time suffer a name change. The permanence of such names as Danube, Thames and Severn and our awareness that the names of many of the great rivers of Europe are Celtic in origin predispose us to regard all names as well-established and immutable. But enquiries in our immediate neighbourhood would elicit in all probability examples of changes which have taken place or which are in progress. In the parish of Mochdre, for example, there is a Cwm Rhiwdre Brook named as flowing into the Mochdre Brook. This tributary is known locally as the Reservoir Brook because it flows through what used to be a reservoir for Newtown but which is now a fish farm. Will there be another