ECONO:\[IC RESOURCES : SALT. 285 



afterwards unsystematically enlarged, until tliey became dangerous. 

 Since the annexation of the Punjab, it has been found useful for facility 

 of collecting the revenue, to lessen their number greatly ; and still 

 further reduction has been proposed or lately carried out. 



The mines open during the progress of the Survey were those of 

 Khewra, Sardi, and Varcha on this side of the Indus, and the open 

 quarries of Kalabagh beyond that river. Besides these, an experimental 

 driving was being sunk (and is intended to be carried on from time to 

 time) beneath the southern cliffs of Mount Tilla, in order to prove the 

 existence or absence of workable salt within reach, that point being 

 so much nearer than the others to the Northern State Railway — not 

 yet completed, but in progress. Up to the latest information the salt 

 had not been reached. 



The largest mines of the range are the Mayo mines at Khewra, so 



called to commemorate the visit of a late Viceroy. 

 Mayo mines. 



In these, vast but dangerous chambers had been 



left by the old Sikh workmen, who either knew or cared so little how 

 or where they worked, that two heavy pillars supporting the roof of one 

 excavation were left resting upon a thin crust of salt, spanning another 

 large chamber below. It has been remarked that most of the roof- 

 falls of the mines took place at night, and the miners, who work only 

 in the day time, may have relied on this poor chance for safety. As it 

 was a matter of great uncertainty how long these pillars would remain 

 supported, instead of supporting the roof above^ their removal was 

 ordered, when suddenly on Sunday the 5th of June 1870 one of them 

 broke through, carrying with it a large part of the roof, and forming a 

 crater on the hill in which the mines are situated. The fallen mass of salt 

 and marl was estimated (by Dr. Warth) at half a lakh of maunds, from 

 which the damage that might have been done had there been miners 

 at work beneath ioaay be imagined. 



The present state of these mines differs widely indeed from that which 

 existed during the earlier visits of the Geological Survey Officers to the 



( 285 ) 



