MINERAL RESOURCES OF THE STATE OF NEW YORK 289 



15 feet or so thick, a single horizontal drift is run from either side 

 of the incline following the strike, at intervals of from 50 to 75 feet. 

 The drift is carried the full width of the bed and connections made 

 by raises with the next level above; after which the talc is removed 

 between the levels, leaving pillars 25 feet or more square, at intervals 

 varying with conditions, to support the roof. With a bed of greater 

 thickness two parallel drifts may be run on the same level, leaving 

 a wall of talc between for support. Heavy pressure on a pillar is 

 liable to bring about its collapse by dislocation at the top or base, 

 especially as there is often a gouge or narrow parting on the one 

 side or the other of the talc. 



Drilling is performed by machines of the percussion type and the 

 holes loaded with dynamite. The talc splits readily along the 

 cleavage planes, following the schistosity of the original tremolite, 

 so as to form slabs which if too large to handle are broken up by 

 sledges. The broken rock is loaded into cars and trammed to the 

 incline, where it is dumped into skips and hoisted to the surface. 



The principal drawback to mining is the considerable and often 

 large flow of water that is invariably encountered, the handling of 

 which necessitates extensive pumping equipment. The water per- 

 colates more or less all through the walls, but the main flow is usu- 

 ally from open seanis which are encountered in the extension of the 

 drifts and which represent faults or crush zones that extend into 

 the country rocks so as to admit of extensive and deep circulations. 

 The water is of surface origin but may be collected from a large 

 area. If the flow is excessive — beyond the capacity of the pumping 

 equipment — . the best plan seems to be to wall up the chamber in 

 which it is encountered. 



There is no uniform practice in selecting or grading the talc before 

 it is sent to the mill. In most mines the foliated talc forms such a 

 small percentage of the whole that it does not affect the quality of 

 the ground product. Certain mines of the southwest end in the 

 town of Fowler yield considerable quantities of the crystal talc, 

 which is kept apart and shipped separately for making special 

 grades of ground talc. It produces a very soft smooth product, 

 lacking the fiber of the more common variety. The attention of 

 the mine workers is directed to the extraction of as little of the 

 unaltered schist and of the gritty talc as possible, and where prac- 

 ticable such material is left in the walls and pillars. Besides tremo- 

 lite there is often more or less free quartz in the fibrous talc. The 

 presence of grit is particularly objectionable in paper stock on 



