228 NEW YORK STATE MUSEUM 



salt, as it is extremely difficult to discriminate between a bed of that 

 kind and an alternating series of salt and shale beds. 



Mining of salt. The production of salt by mining conducted 

 through shafts sunk to the beds has been in progress in New York 

 since 1885, when the first shaft of the Retsof Mining Co. at Retsof 

 was bottomed. In the following few years other shafts were put 

 down; one 2^ miles south of LeRoy, Genesee county, by the Lehigh 

 Salt Mining Co. ; one at Livonia, Livingston county, by the Livonia 

 Salt & Mining Co.; and one at Greigsville, Livingston county, by 

 the Greigsville Salt & Mining Co. In 1906 the Sterling Salt Co. 

 completed a shaft at Cuylerville, Livingston county. The last shaft 

 to be put down is that of the Rock Salt Corporation at Portland 

 Point on Cajoiga lake which was completed early in 19 18. 



Underground mining has an advantage over the method of 

 extraction by brine wells on the basis of production costs. Its 

 disadvantage inheres in the impure quality of the product, which 

 necessarily contains more or less of the admixed calcium and 

 magnesium compoimds, which in the process of brine evaporation 

 are largely removed. Rock salt, however, finds extensive uses, 

 and the consumption has grown more rapidly of late years than 

 of evaporated salt. 



The mining operations are not essentially different from those 

 employed in working a fiat coal seam on the room-and-pillar method. 

 Main galleries are extended east and west which serve as permanent 

 haulage ways, and then headings are driven at right angles, at 

 regular intervals, dividing off the ground into panels. The pillars 

 measure 30 feet on the side and are spaced 30 feet apart, in the 

 usual practice. This results in the removal of 75 per cent of the 

 actual working thickness. In the mines in Livingston county, the 

 only ones that have been extensively worked, the portion of the 

 bed suitable for mining ranges from 6 or 7 feet to 12 feet thick. 



The salt is broken by drilling a series of holes with rotary auger 

 drills and charging the holes with dynamite. In the ordinary run 

 a hole is 6 to 7 feet in depth and can be drilled in about 3 minutes. The 

 auger is i| inches diameter. Electric power is now used. It would 

 seem practicable to undercut the salt, as is done in mining soft coal, 

 but the trials that have been made with coal-cutting machines have 

 not been successful. The salt is said to possess a degree of toughness 

 that greatly lowers the efficiency of such machines even to make their 

 use impracticable, at least in their present forms. 



The broken salt is loaded on to cars which are drawn by mules to 

 the main haulage ways; then they are made up into trains to be hauled 



