MINERAL RESOURCES OF THE STATE OF NEW YORK 229 



by electric locomotives to the shaft. The steel cars hold 3 tons each. 

 These are loaded both by hand and by automatic shovels, the use 

 of the latter having been taken up quite recently. 



At the shaft the cars are run on to cages and hoisted to the top of 

 the breaker. There are two hoisting compartments in each shaft, 

 the cages being operated in balance, and the usual rate is about a 

 car each minute, the distance to the top of the breaker being 11 50 

 feet. At the breaker the car is dumped into a bin from which it 

 goes through the process of crushing and screening to provide the 

 various sizes in demand. These include lump salt, large and small 

 and 5 graded sizes, ranging from three-quarters to one-sixteenth of 

 an inch in diameter. 



During the last several years the only active mines have been those 

 of the Retsof Mining Co. and the Sterling Salt Co. The shaft at 

 Portland Point has not been equipped for production. 



Manufacture of salt from brine. The making of salt by evapora- 

 tion of brines, or water solutions of salt, is the really essential branch 

 of the industry, so far as concerns the majority of uses. Brine 

 salt may fill the place of rock salt in practically all applications; 

 the relative cheapness of the latter is the principal factor in the 

 development of the market for mined salt. It is only by evapora- 

 tion that the impurities which are invariably present in the natural 

 salt or brines may be removed and the product made fit for htiman 

 consumption. These impurities consist largely of calcium and mag- 

 nesium compounds, of which the latter are obnoxious because of 

 their bitter taste and medicinal qualities. Calcium chloride has a 

 great affinity for water and causes the salt to cake when exposed to 

 the air. 



The methods of salt manufacture that have been employed in 

 New York State include the following: (a) solar evaporation; (6) 

 evaporation by direct heat in open kettles or pans ; (c) evaporation by 

 steam with jacketed kettles or grainers; (d) evaporation by steam 

 in vacuimi pans. 



Solar evaporation is the, process in use for the natural brines found 

 on the old Onondaga reservation near Syracuse. It was first em- 

 ployed in 1 82 1, previous to which time the salt was made in open 

 kettles by direct heat. Both methods were in use until a few years 

 ago, when the kettle process was discontinued, and all the salt now 

 made at Syracuse consists of the coarse solar variety. The evapora- 

 tion is carried out in shallow wooden vats, of which one kind known 

 as aprons in which the brine is only about one-half of an inch deep 

 performs the first step in the concentration, raising the salinity to a 



