62 Proceedings of the lloyal Irish Acade»ii/. 



mountain sides increase its body in water to a mighty torrent. "Water- 

 worn gold in scales, grains, and dust, is found along its banks ; 

 thruughout its course into tbe Navia, a distance of 15 miles, and 

 afterwards along this river's banks for a further distance of 5 miles." 

 The river Castelo, draining another watershed, but having its source 

 on the opposite side of the western divisory of the Orua, is also auri- 

 ferous. This river passes below the delris from the ancient workings 

 known to-day by the name " La cueva de Juan Rata^'' mentioned in 

 the Mining Journal of February 24th, 1894. The river Bao drains 

 the Purnovo Mountain. Here, too, there are a number of ancient 

 workings, and formerly washings were carried on yearly in this river. 

 Both these rivers are tributaries of the Porcia. The excavations and 

 delris of all these show the enormous mass of stuff handled, and it is 

 to be presumed that the results obtained were in proportion. In the 

 upper waters of the river Ibias, summer pannings have always been 

 carried on. Here there are no ancient workings. The gold has been 

 transported from the weathering of the Sierra de Tablado, comprising 

 a continuation of the Yalldor quartzites, and the gold of the washings 

 that are carried on, on the upper reaches of the river Navia, has been 

 brought from the weathered Sierra de Bastelo, which has an altitude 

 of 1680 m. above sea level. I^either in the one, nor in the other of 

 these, are there any landmarks, in the shape of ancient workings to 

 guide one. The absence of workings is explained, if we bear in mind 

 the climatic differences of summer and winter. Heat in summer, and 

 a long winter of snowfalls, a district scarcely populated, the long 

 distance from the sea coast, and at the time of the ancient occupation, 

 an almost impenetrable region, comprised of mountain fastnesses and 

 deep ravines infested by wolves and bears. 



It is stated in the Mining Journal': — "These (quartzites) of 

 the western portion continue into the province of Leon, and present 

 themselves as a guide to the goldseeker. Following then this quartz- 

 ite belt over the divisory Cantabrian range, through the pass called 

 the ' Puerto de Trayeto,' at an altitude of 1450m. above sea level, 

 we find it continuing in a south-west direction on the southern flank 

 of the range. This district is drained by the rivers Sil, Burba, 

 Anclares, and Qua, all of whose beds and banks are auriferous. Thus 

 it continues to Las Medulas and Puente de Domingo Plores. Here it 

 changes to a south-east direction, and continues for many leagues 

 until it is cut off by the mountain range that divides the province of 



1 July 28, 189G, p. 946. 



