Natural History in Foreig7i Countries. 285 



was observed to pass through these ridges, having its surface covered with 

 loose black sand, down which fragments of rocks ejected from the crater 

 continually descended. 



After twelve hours of incessant fatigue the author gained the highest 

 point of the mountain on the western side of the crater, 17,884 ft. above 

 the sea ; at which station the mercury in the barometer subsided to 15'63 

 in., and the temperature indicated by the attached and detached thermome- 

 ters, was, respectively, 39° and 33° Fahr. at 5 o'clock P.M., when exposed to 

 the direct rays of the sun. The plain of Mexico was enveloped in a thick 

 haze, and the only distant objects visible at that time, were the volcanoes 

 of Orizaba and Iztaccihuatl. The crater of Popocatapetl appeared to ex- 

 tend one mile in diameter, and its edges, of unequal thickness, descended 

 towards the east. The interior walls consisted of masses of rock arranged 

 perpendicularly, and marked by numerous vertical channels, in many places 

 filled with black sand. Four horizontal circles of rock, differently coloured, 

 were also noticed within the crater ; and from the edges of the latter, as 

 well as from its perpendicular walls, several small columns of vapour arose 

 smelling strongly of sulphur. The noise was incessant, resembling that 

 heard at a short distance from the sea shore during a storm ; and at inter- 

 vals of two or three minutes the sound increased, followed by an eruption 

 of stones of various dimensions ; the smaller were projected into the ravine 

 before mentioned, the larger fell again within the crater. 



The sensations experienced by the author were analogous to those usu- 

 ally felt by travellers at considerable elevations; viz. weariness, difficult 

 respiration, and headache, the latter inconvenience having been first per- 

 ceived at a height of 16,895 ft. Tobacco smoke and spirituous liquors were 

 also found to produce an unusually rapid effect upon the sensorium. {Pro- 

 ceedings of the Geological Society of London, 1827-28. No. vii. p. 76.) 



SOUTH AMERICA. 



The Biscacho, or Coquimbo Owl 

 (Strijr cunicularia). {fig. 150.) — This 

 bird, Captain Head observes, is 

 found all over the plains of the 

 Pampas. Like rabbits, they live in 

 holes, which are in groups in every 

 direction, and which make galloping 

 over these plains very dangerous. 

 These animals are never seen in the 

 day ; but, as soon as the lower limb 

 of the sun reaches the horizon, they 

 are seen issuing from their holes in 

 all directions, which are scattered in 



groups like little villages all over the 



Pampas. The biscachos, when full-grown, are nearly as large as badgers, 

 but their head resembles a rabbit's, except that they have large bushy 

 whiskers. In the evening they sit outside their holes, and they all appear 

 to be moralising. They are the most serious-looking animals I ever saw ; 

 and even the young ones are grey-headed, have mustachios, and look 

 thoughtful and grave. In the daytime, their holes are always guarded by 

 two little owls, who are never an instant away from their posts. As one 

 gallops by these owls they always stand looking at the stranger, and then 

 at each other, moving their old-fashioned heads in a manner which is quite 

 ridiculous, until one rushes by them, when fear gets the better of their 

 dignified looks, and they both run into the biscacho's hole. {Head's 

 Rough Notes, p. 82.) 



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