CAVERNS. 



243 



pasture in which the chasm is situated, having lost cattle by falling into it, made the 

 attempt to fill it up, and threw down many loads of stones without any visible effect, some 

 of which were probably those which choked the aperture reached by Mr. Lloyd. The 

 whole extent and actual depth of Eldon Hole have not therefore been ascertained. 



There is a second kind of caverns which are essentially distinguished from the first by 

 the circumstance that they reach the daylight at both ends, piercing through the rocks in 

 which they are situated, and forming natural shafis. Their appearance is very remarkable 

 when they occur on the top of isolated mountain-peaks, or of independent masses of rock ; 

 and when they are so straight that the day-light appears through them, they present a 

 very remarkable aspect, and have been designated by the name of transparent caverns. 

 On this account, the so-named Martin's hole is particularly celebrated. It penetrates the 

 Tschingel-peak, one of the highest mountains of the Dodi chain ; and twice in the year, 

 in March and in September, the sun appears as if through a pipe, and gives to the valley 

 beneath a highly singular and pleasing light. A similar phenomenon has been described 

 by Pontoppidan as occurring in Norway, where there is a perforation of the mountain of 

 Torghatten in Helgeland, of fifty fathoms in height, and a hundred fathoms in length, 

 through which the daylight appears. Like phenomena present themselves at the hollow 

 stone of Muggendorf ; likewise in Saxon Switzerland, and a, whole series of these per 

 forations occur on the coast of the island of Heligoland, and on the coast of New 

 Zealand. 



The third and most frequent form of caverns is unquestionably that in which there is a 

 series of extensions of nearly similar height and direction, which are connected with each 

 other by passages of greater or less extent. This is the form of the caverns of the Hartz, 

 the cave of Caripe visited by Humboldt, of Antiparos, and of the Peak of Derbyshire, 

 __^^_ the entrance to which, with 



the castle on its summit, is 

 here represented. This is 

 also the form of the more im 

 portant caves of Franconia. 

 The extent of these penetra 

 tions into the mountains, in 

 particular of such as are si 

 tuated in limestone, is often 

 very extraordinary. In 

 many of them the extremity 

 has never been reached ; 

 and it appears from con- 

 curreat testimony that some 

 of them have been explored 

 for more than a mile in 

 length. In this respect, the 

 cave of Adelsberg, six miles 

 from Trieste, is mentioned 

 as the greatest of all, excel 

 ling all known caverns, not 

 only in length, but in 

 height. Deep abysses of five 



and six hundred feet often occur in it ; and in one of these, it was found necessary to give 

 up the attempt to proceed farther. The entrance resembles a fissure in a huge rock caused 

 by an earthquake. Here torches are always lighted to conduct visiters. The cavity itself 



Pcveril of the Peak's Castle, with the mouth of the Cave. 



