THE VOYAGE OF THE BEAGLE 341 



At the present day, even in the most retired Sounds on the 

 coast of Tierra del Fuego, the currents in the transverse 

 breaks which connect the longitudinal channels, are very 

 strong, so that in one transverse channel even a small vessel 

 under sail was whirled round and round. 



About noon we began the tedious ascent of the Peuquenes 

 ridge, and then for the first time experienced some little 

 difficulty in our respiration. The mules would halt every fifty 

 yards, and after resting for a few seconds the poor willing 

 animals started of their own accord again. The short breath- 

 ing from the rarefied atmosphere is called by the Chilenos 

 " puna ;" and they have most ridiculous notions concerning 

 its origin. Some say " all the waters here have puna ;" others 

 that " where there is snow there is puna ;" and this no 

 doubt is true. The only sensation I experienced was a slight 

 tightness across the head and chest, like that felt on leaving 

 a warm room and running quickly in frosty weather. There 

 was some imagination even in this; for upon finding fossil 

 shells on the highest ridge, I entirely forgot the puna in my 

 delight. Certainly the exertion of walking was extremely 

 great, and the respiration became deep and laborious: I am 

 told that in Potosi (about 13,000 feet above the sea) strangers 

 do not become thoroughly accustomed to the atmosphere for 

 an entire year. The inhabitants all recommend onions for 

 the puna; as this vegetable has sometimes been given in 

 Europe for pectoral complaints, it may possibly be of real 

 service: for my part I found nothing so good as the fossil 

 shells ! 



When about half-way up we met a large party with sev- 

 enty loaded mules. It was interesting to hear the wild cries 

 of the muleteers, and to watch the long descending string 

 of the animals ; they appeared so diminutive, there being 

 nothing but the black mountains with which they could be 

 compared. When near the summit, the wind, as generally 

 happens, was impetuous and extremely cold. On each side of 

 the ridge, we had to pass over broad bands of perpetual 

 snow, which were now soon to be covered by a fresh layer. 

 When we reached the crest and looked backwards, a glorious 

 view was presented. The atmosphere resplendently clear; 



