PAN PROCESS 49 



calcium sulphate in the former is very rarely deprived of 

 its water of crystallization, and therefore the pan salt will 

 usually dissolve perfectly clear in water. 



At the works of the Globe Salt Co. at Wyoming and at 

 those of the Leicester Salt Co. at Cuylerville a modified 

 pan process was used which is described as follows by Mr. 

 I. P. Bishop: 



The Lewis Process 

 "The Lewis process is a modification of the pan process, 

 and is so called from its inventor, Mr. Sylvester Lewis, of 

 Rochester. The evaporating apparatus consists of ten pans 

 20x10 feet, each on an arch with its own grate and flue. 

 There is also one long pan 15 x 100 feet with a grate at each 

 end. The hot gases from the smaller flues are made to 

 pass under the larger pan and thus lose the greater part of 

 their heat before passing to the chimney. The brine is 

 heated to 220 Fahr., in the larger pan to. precipitate the 

 gypsum, and then drawn to the smaller pans to be evapo- 

 rated. The principal advantage claimed for this process over 

 the preceding, is that any pan can be removed for repairs or 

 for cleaning without stopping the work in the others." 



B. The Onondaga Kettle Process 

 This is exclusively employed on the Onondaga Salt Reser- 

 vation. A "Salt Kettle Block" usually called a "Kettle 

 block " consists of from 60 to 100 hemispherical cast-iron 

 kettles suspended or hung on "lugs" or pins in two parallel 

 flues, called arches, ending in one chimney, which has a 

 height of 50 to 100 feet according to the length of the flues. 

 In front the arches are provided with cast-iron flat-topped 

 grates 3 feet in width and 5 feet long, perforated with holes 

 I inch in diameter and one inch apart. These are well adapted 

 for the burning of anthracite dust or culm which is now exclu- 

 sively used for this purpose. The necessary artificial draft 

 is furnished by a pressure blower. The kettles are from 22 

 7 



