EASTERN PLATEAU. 159 



exhibited by the old workers, and the result has been constant danger 

 and tremendous falls — a large one having taken place so late as 1870, in 

 consequence of a huge supporting pillar having been undermined, and 

 left standing over a lower chamber, upon a comparatively thin shell, 

 which it eventually broke through. When the mines were visited in 

 1869-70^ the position of some of the miners was anything but enviable; 

 perched upon a lofty tripod of slender sticks, picking at the roof of one 

 of these high chambers, a roof probably full of fissures and utterly un- 

 supported for many yards ; while in other places, considered still more 

 dangerous, huge masses of salt-rock between the fissures impended like 

 the displaced key-stones of enormous arches.* The heavily-laden women 

 and children struggling up the well-made incline of " Purdon's tunnel ■" 

 had evidently, bad as it was, the better place. 



The beauty of the interior of these mines has often been noticed ; their 

 extent appears more impressive than their smoke-begrimed sides and 

 roof, but the effect, when they are lighted, is very fine ; lines of small 

 lamps at difierent levels and inclinations marking those places in the vast 

 chambers where footing can be had, while some hay set on fire here and 

 there, for a few moments, lights up portions strongly, others vanishing 

 in distance or in smoke. 



The mines have been excavated, some in the same and some in differ- 

 ent beds of salt, all of which lie in the upper 

 Position of the mines. 



portion of the marl, though most of the worked 



bands occur at a considerable depth from the surface. The following is 

 their arrangement according to Dr. Warth, from the purple sandstone 

 downwards (see section fig. 24, Plate XVII). 



Feet. 

 14. White gypsum, average .., ... ... ... 5 



13. Brick-red marl or gypsum (i. e., gypseous marl) 

 12. Brown gypsum (? purple gypseous marl) 

 11. Lower layer of white gypsum 



Salt marl and salt ... ... 



... 130 



... 140 



... 200 



550 to 600 



* I was told that the workmen preferred these localities to places where the salt was 

 more solid, because a single blast in such a situation detached more of the mineral. 



{ 159 ) 



