472 



The difference of the indications of the two Thermometers expresses, 

 numerically, the degree of atmospheric dryness at the moment to which 

 it refers, and thus presents a scale the zero of which is saturation, the 

 maximum being unascertainable. 



LI. — Megalithic Remains in the Department of the Basses Pyre- 

 nees. By Lord Talbot de Malahide, President R. I. A. 



[Read April 26, 1869.] 



During my stay at Pau, I made the acquaintance of the Vicomte de 

 Villemarque, a distinguished antiquary of Brittany, who has given much 

 attention to what they call Celtic antiquities. He informed me that 

 within a short distance there were some remarkable monuments of this 

 period — indeed, the only ones he was aware of south of the province of 

 Poitou. We accordingly arranged for an expedition to visit them, and 

 we were fortunate enough to secure as a - companion General Sir Vincent 

 Eyre, to whose ready pencil I am indebted for the accompanying sketches. 

 I regret extremely that owing to circumstances we were not enabled to 

 give as much time to the investigation of these monuments as I could 

 wish. There was a good deal of snow on the ground, and I did not 

 make any measurements, relying upon obtaining this information in 

 detail from another source, in which I have been disappointed. 



After passing the picturesque and woody sub-Pyrenean region, we 

 emerged on the Yal d'Ossau which leads to Eaux Bonnes, and stopped 

 at Bielle. This is the site of a Roman town, and mosaics of that period 

 have been discovered there. 



However, neglecting them, we left the beaten road, and penetrated 

 into the flanks of the main chain of the Pyrenees. The scenery was 

 very fine, commanding as we did the beautiful Yal d'Ossau, and enveloped 

 by an amphitheatre of mountains. Between three or four miles from 

 Bielle, we got into the snow, and found ourselves in a circular valley, 

 with a stream running down, a humble chapel, and a plateau surrounded 

 by a circle of chestnut trees, in the midst of which was the most 

 remarkable of the circles which came under our observation. The spot 

 is called, in the dialect of Beam, JSondaas de las Hadas, or Spring of the 

 Fairies (see PI. xxxi.). In the month of May I understand that there are 

 great festivities among the peasantry, who dance and amuse themselves 

 under the trees. It is considered a blessed spot, and no evil spirit ventures 

 to disturb their innocent enjoyments. The spring has a still holier 

 character ; it is under the protection of the Yirgin Mary, and its waters 

 were held to be a sovereign remedy against the rinderpest when it first 

 invaded the South of Europe, about the middle of the last century. The 

 chapel was then erected, and I believe the patron saint is considered to 

 have exerted a prophylactic influence during the prevalence of the late 

 Peste bovine. 



