64 NEW YORK STATE MUSEUM 



The mines at Akron and Oakfield, as well as those of th"e Con- 

 solidated Wheatland Co. at Wheatland and the Garbutt Gypsum 

 Co. at Garbutt are entered through vertical shafts from 50 to 70 

 feet deep. The shafts have either two or three compartments, one 

 of which serves for a ladder and airway. The underground work- 

 ings follow the room and pillar system but are more regularly 

 planned than these of the adit mines and are based on accurate 

 surveys. The early methods of extending the drifts radiately from 

 the shaft or in a haphazard manner are no longer pursued to any 

 extent. The mines are often electrically lighted, ventilated by 

 forced draft and when necessary are drained by pumps wliich raise 

 the water from a sump at the shaft bottom. Gas, electricity and 

 steam are used for power purposes, tHie former being supplied froin 

 the natural gas belt of western New York. Electric locomotives 

 have been recently introduced for underground haulage, but in. most 

 mines the cars are either pushed by hand or drawn by mules. The 

 hoisting is accomplisbod in various ways. At the Garbutt mine a 

 derrick and boom raise the rock which is loaded into a metal scoop. 

 The American Gypsmii Co, has installed at Akron a bucket elevator. 

 Single and balanced platform hoists which raise the gypsum in the 

 mine cars are most generally employed. 



The rock is broken by drilhng and blasting. Auger drills are 

 used in some mines and percussion drills in others, the former being 

 employed when the rock is suffioiently soft. With hard or tough 

 rock tliey are apt to become heated and to bind in the holes. Some 

 companies prefer to let the mining on contract, while others main- 

 tain the wage system. The miners represent all nationalities but 

 are mainly from southern Europe. A few Indians from the New 

 York reservations are employed. 



The mines are usually connected with the miUing plants by 

 tracks. In the Fayetteville district, however, the rock is teamed, 

 except in one case where a traction engine is used to draw a 20-ton 

 wiagon, and the haulage is here an important item of the working 

 co'Sts. Much of the output of this section is shipped in lumps or 

 ground form to cement and plaster mills outside the district. 



ORIGIN OF GYPSUM 

 General principles and theories 



Gypsum is formed by the combination of sulfuric acid with lime 

 in the presence of water. The sulfuric acid need not necessarily be 

 in free state, since almost any soluble sulfate may react upon lime 



