THE MINING AND QUARRY INDUSTRY I908 87 



United States Talc Co. and the several properties of the Interna- 

 tional Pulp Co., the largest producer in the district. A new com- 

 pany, the Uniform P^iber Talc Co., is at present opening a mine 

 just west of Talcville. 



Mining is all underground. The general practice in the district 

 does not differ materially from the method employed in working 

 other deposits which are similarly situated, though of course the 

 soft and slippery nature of the material necessitates that the pillars 

 left for roof support should be of large size. The workings are 

 reached through inclines carried down on the footwall. In case 

 the bed is not over 15 feet or so in thickness a single drift is run' 

 from either side of the incline at intervals of about 50 feet. The 

 drift is carried nearly the full width of the bed and connected with 

 the level above at short intervals by upraises, after which the talc 

 is removed between the levels, leaving pillars 25 feet square or more 

 to support the roof. With a bed of greater thickness two drifts 

 may be run on the same level, leaving a wall of talc between to 

 assist in supporting the roof. 



Both machine drills of the percussion type and hand drills are 

 employed in the mines. The talc is easily penetrated, though the 

 holes must be cleaned at frequent intervals to prevent binding of 

 the drills, and on that account the machines have not the usual 

 advantage over hand work as regards economy. The rock is 

 blasted by dynamite. It splits readily along the bedding or cleav- 

 age planes. The large blocks or slabs from blasting are reduced 

 by sledges to a size convenient for handling. From the stopes the 

 talc is loaded into cars and run out to the incline where it is 

 dumped into skips for hoisting to the surface. It is aimed to leave 

 the gritty and impure talc in the walls and pillars and to send only 

 the milling grade to the surface. 



Preparation for the market. The processes in use for grinding 

 and preparing the talc have been gradually evolved out of long- 

 continued experimentation. It is said that the first prepared talc 

 sent from the district was ground in a gristmill. With the dis- 

 covery of the value of the fibrous variety as a paper filler attention 

 was given to the methods of treatment which have been perfected 

 until the various grades now marketed arc recognized as standard 

 and find general favor in the paper trade. The development of the 

 industry began to take on a permanent character about 1880 and 

 in the next decade attained nearly its present importance. 



