Th£ mining and quarry industry 1913 67 



ings are laid out in panels, with the main galleries running east- 

 west. The headings are driven to the north so as to secure advan- 

 tage of the dip in tramming the salt to the main haulage ways. Of 

 the 20 feet or more of salt only about 12 feet are actually mined, 

 the remainder being left in the roof and floor. The breast of salt 

 is worked in two benches. The rooms are 30 feet wide, separated 

 by equally wide pillars. There is no timbering, and of course no 

 drainage to provide for in the workings. The salt is drilled by 

 rotary auger drills run by compressed air. The holes are placed 

 with a view to making the greatest proportion of lump salt, and 

 they are charged lightly with low-grade dynamite. Charging and 

 blasting are performed by a separate crew, with one man for each 

 pair of drillers. The broken salt is loaded into three-ton cars 

 which are run down to the main haulage ways and from there hauled 

 to the shaft. At the surface the salt is crushed and the various 

 sizes separated by screening. The coarsest lumps are sold un- 

 crushed, principally as cattle salt. The crushed and screened salt 

 finds use in the curing of hides, refrigeration, in the manufacture 

 of oleomargarine, and in various other industries. An analysis of 

 a sample of the New York salt, as given by Merrill, follows : 



NaCl : ; . 98.701 



MgCl 2 .055 



CaCl 2 .018 



CaS0 4 .484 



Moisture trace 



Insoluble . 743 



Brine salt. The manufacture of salt from brine is carried on 

 either by the solar process, in which the brine is led into shallow 

 wooden vats and there exposed to evaporation by the sun's heat, or 

 by artificial methods which depend upon evaporation by direct fire 

 or steam of the brine contained in kettles, pans or vats. The open 

 kettle process of artificial evaporation was long used at Syracuse, 

 but has now been superseded by the solar process. The methods 

 of artificial evaporation now in general use are the grainer, open 

 pan and vacuum pan. Some of the plants make use of only one 

 method; others have an equipment that combines the grainers with 

 vacuum pans or grainers with open pans. 



The manufacture of solar salt at Syracuse is still an important 

 industry in which a large number of individuals and firms are 

 active. The product varies considerably from year to year, de- 

 pending on the character of the season. The salt is marketed 



3 



