104 LITEEATURE ON TOEEBNTS, 



" A journey of a few hours (says he) may enable any one, from the -window 

 of a carriage, to verify the greater part of the observations made. From the 

 railway station of Hendaye, which is on the shore of the Ocean, may be seen 

 on adjacent rooks the covering of loess, and the torrential pebbles. 



" In the cuttings towards Biaritz and Bayonne, the bank of gravel is well 

 marked, and from place to place very deep and extensive. From Peyre- 

 horade to Pau, the railway follows closely the foot of a terrace, the slope of 

 which often presents a remarkable regularity. It is the base of a cone oast 

 up on the tertiary deposit by the Gave de Lourdes. The town of Pau is 

 built on the edge of this terrace. From the Place Eoyale we look down 

 upon the valley of the Gave, some 30 mfetres, or 100 feet beneath ; opposite, 

 on the left bank of the river, the undulating knolls of Jurangon are remains 

 of the glacier deposits of the Gave d'Ossau ; on the right bank towards the 

 east, and on to the mountains stretches in dimishing perspective the valley, 

 divided in its primary plan by a small chain of low hills, crowned with villas 

 and small umbrellarlike pines ; these are testimonies to the work of erosion 

 committed by the Gave when it opened up its channel and valley through 

 its own deposits. The horizon is bounded towards the northeast by a 

 straight line of regular inclination, which is the culminating ridge of the 

 cone of Lourdes. 



" From Pau to Nay the plain is sown with rolled and water-worn pebbles. 

 From Nay to Saint-P6 the grounds show, from time to time, the unmoved 

 rocks covered with loess and glacier pebbles, and once and again terraces 

 cut up by the Gave in its own deposits. From Saint-P6 onwards appear 

 mwaine blocks, which continue to appear until Lourdes is reached, and 

 the spaces between these morairies are filled with pebbles rolled by the 

 torrents. Lourdes is the highest point of the railway, corresponding at 

 once to the summit of an angie which formerly divided the glacier into two 

 branches, and to the summit of the glacier-deposited cone ; the latter is on 

 the hiUs which rise to the left of the railway station. The B16out, with its 

 erratic boulders, rises on the right of the station, and partially encloses the 

 valley of Argelfes. 



" On leaving Lourdes the road descends towards Tarbes by a riverless 

 valley ; and between Lourdes and Ad6 there have been counted, in the rail- 

 way cuttings, seven separate and distinct moraiTies, partially buried under 

 the argillaceous loess and the torrential deposits. 



" The line proceeds for some way between the two cones of the Gave and 

 of the Adour ; but thereafter the plain expands through the erosion eifected 

 by two parallel water-courses. The Echez, pretty far to the right, is still 

 eating away a scrap of the cone of the Adour ; while on the left bank the 

 Mardaing is attacking the cone of the Gave, the fine regular ridge of which 

 may be seen after passing the station of Ossun. 



" In approaching JuUian the railway passes through a cutting in descend- 

 ing a terrace cut up by the Echez in the dejection of this torrent, which 

 took its rise towards Ad6 from the eastern branch of the glacier. The 

 strength of this torrent, now no more, is still testified by the dimensions of 

 the blocks of stone which it has rolled down and spread over the plain. 



" From Tarbes to Tournay the tunnels and cuttings are cut under the 

 loess of the Adour, and we traverse several open valleys following the crest 

 of the cone. The rails at Tournay pass over the Arros, which flows between 

 the glacier dejections of the Adour and those of the Neste, and rises, as the 

 cone of the Neste, by an inclination of -034 along the valley of the Leue. 



