ABRASIVE MATERIALS 433 



proved agricultural machines have not yet Ijeen intnKliiced. 

 Thus, while the production of scythestones in the United States 

 has remained about the same, it has become necessary to seek 

 a market for them in foreign countries, and a considerable pro- 

 portion of the production is exported. 



The whetstone producing!; rocks are all sedimentary in 

 origin, and include quartz-mica-schist, sandstone, novaculite, 

 and intermediate rocks. These are found abundantly in vari- 

 ous localities, so that there are probably but few countries 

 which have not within their ])orders a supply of some kind of 

 stone suitable for making whetstones. Although the material 

 for manufacturing whetstones is so common, only those (quar- 

 ries which produce stones of superior cjuality and have tlie 

 greatest advantages tor manufacturing and shipping can sur- 

 vive the competition in the trade. This is of course the reason 

 the production of whetstones is confined to a few localities. 

 Occasionally a stone is found of exceptional quality, as the 

 novaculite of Arkansas, for which there is a large demand, 

 although the price may be much higher than that of other 

 whetstones. At the present time the domestic supply of whet- 

 stones is obtained from Arkansas, Indiana, Ohio, New Hamp- 

 shire and Vermont. There is undoubtedly considerable whet- 

 stone material utilized in other states, but those mentioned 

 are the only ones that have produced this abrasive for the mar- 

 ket. 



At the whetstone quarries in Arkansas, wliich are in Gar- 

 land and Sahne counties, principally at or in the vicinity of 

 Quarry or Whetstone mountain, Garland county, there is ob- 

 tained the novacuhte (sandstone) from which is manufactured 

 the best and most valuable natural oilstone or whetstone on 

 the market. The quality of the rock varies greatly, even in 

 different parts of the same quarry, but two distinct types of 

 stone or grit are recognized, which are known on the market 

 as the Arkansas and Washita. The latter is less dense and 

 much more porous than the Arkansas. Both of these t>T^es 

 are divided into two grades, known as soft and hard. They 

 are used principally in the form of small wheels, oilstones of 

 different shapes, and points such as are used by engravers, 



Vol. 6—38 



