INTENSE COLD. 35 



and impressive custom, which we observed throughout our 

 travels in Yucatan. The cold was so intense during the 

 night that I awoke several times actually suffering from its 

 effects. During the day the sun beats down upon the earth 

 with intense force. The rapid radiation at night sometimes 

 produces cold intense enough to cause water to freeze. 



In the morning, after a refreshing bath, we shouldered 

 our guns, insect boxes, and pouches, and walked into the 

 woods covering the north side of the Sierra. On our way 

 we saw numbers of swallows, flycatchers, and hawks. 

 Their shrill cry was often heard, with now and then the 

 loud tapping of a woodpecker. We were not successful in 

 shooting, and in about an hour were joined by the rest of 

 the party on horseback, on their way across the Sierra to 

 visit the large cave of which I spoke before. After passing 

 the summit of the Sierra, we descended twenty feet or more 

 to the mouth of the cave. 



This was in the form of a circular well, thirty feet in 

 diameter and twenty in depth; descending this we found 

 ourselves in a circular chamber, from which numerous pas- 

 sages branched to right and left. At one corner was a rude 

 natural opening in a great mass of limestone rock, low and 

 narrow, through which rushed a powerful current of air, 

 agitating the branches and leaves in the immediate vicinity. 

 At the distance of a few feet the descent was precipitous, 

 and we went down by a ladder about twenty feet. Here all 

 light from the mouth of the well was lost; but we soon 

 reached the brink of a very steep descent, to the bottom of 

 which a strong body of light was thrown from a hole in the 

 surface, a perpendicular depth, as we afterward learned, of 

 one hundred and ten feet. As we stood on the brink of 

 this precipitous path, under the immense shelving mass of 

 rock, seeming darker from the stream of light thrown down 

 the hole, gigantic stalactites and larger.blocks of stone as- 



