92 JOURNAL OF THE 



DRESSING THE ROUGH MICA. 



The rough mica is hoisted from the mine in blocks of consid- 

 erable size, weighing from 50 to 250 pounds, tabular in shape, 

 and more or less contaminated with fragments of feldspar, quartz, 

 waste mica, etc. It is the purpose of the dressing to free the 

 blocks from all materials not made use of in preparing cut mica. 

 This is all done by hand, and consists in cleaving a block with 

 thin steel wedges aloug the planes of lamination, separating it 

 into a number of tabular pieces about J inch thick, and as large 

 as the stock will allow. These pieces are then further cleaved 

 until the proper thickness for cut mica is attained, this being, 

 according to the use it is to be put to, from J to y 1 ^ inch, or even 

 thinner. The workman doing this also frees the sheets from ad- 

 hering quartz, fragments of mica, etc., and passes them to the 

 "seriber." 



Scribing is an operation demanding a considerable degree of 

 skill and experience. Upon it depends the yield of cut from 

 block mica. It is performed by laying upon the sheet the pat- 

 tern by which it is to be cut, and marking or scribing around ir 

 with a knife or similar instrument. The patterns are pieces of 

 tin, sheet-iron, etc., with the shape and size determined by the 

 order from the mica brokers or dealers in the lar«;e cities, or bv 

 the stove maker himself. In Mitchell county alone there are 

 about 100 different patterns, and their shape and size is constantly 

 varying according to the fashion of the stove windows. The 

 size of cut mica was formerly of much greater consequence than 

 at present. Several years ago there was a regular and systematic 

 increase in value with the increase in size, the quality of course 

 remaining the same. This is true to some extent now, though 

 there appears to be a decided tendency towards smaller patterns. 

 The first noticeable change in this respect was perhaps in 1 883— '84, 

 when the stove manufacturers were compelled by the scarcity of 

 large mica to use smaller sheets. They found the change so ad- 

 vantageous to their pockets that they persevered in it, and thus 

 influenced the mica trade no little. 



