432 JOSEPH HYDE PRATT 



Although sandstone suitable for the manufacture of 

 grindstones is not uncommon, the variety adapted to the manu- 

 facture of a pulpstone is somewhat rare. A considerable de- 

 mand for pulpstones rose when paper began to be manufac- 

 tured from wood pulp. In this manufacture a stone is re- 

 quired that can be run in hot water. The Peninsula grit ob- 

 tained from Peninsula, Tippecanoe, and Empire, Ohio, if care- 

 fully selected, ought to make a good pulpstone, which should 

 easily compete with that imported from Newcastle-upon-Tyne, 

 England. 



The natural grindstone manufactured from sandstone 

 was formerly in universal use in all kinds of manufacturing 

 plants and in the household, but there has been introduced 

 successfully during the past ten years a grindstone made from 

 emery or corundum. While at the present time only the 

 smaller sized grindstones for household use are made of these 

 materials, it is possible that in the near future large wheels 

 will be made that will rival some of the larger grindstones. 



The terms oilstone, whetstone, and scythestone are used 

 somewhat ambiguously, and often the same stone when used 

 for one purpose will be called an oilstone, and when used for 

 another purpose a whetstone, or even a scythestone. The 

 term oilstone has come to be applied to all stones used for 

 sharpening mechanics' tools, for the reason that it is neces- 

 sary to use oil on most of them to prevent the stone from be- 

 coming hot and thus heating the tool, and also to prevent the 

 small particles of steel that are ground off the tools from enter- 

 ing into the pores of the stone. 



A considerable change is noticeable in the oilstone, whet- 

 stone and scythestone industry in respect to the stone that 

 has the greatest use. While the sale of oilstones and whet- 

 stones has increased, or at least held its own, in the United 

 States since 1889, there has been a considerable falling off 

 in the sale of scythestones. This is undoubtedly due to the 

 small number of scythes, sickles, etc., used at the present 

 time, these having been largely replaced by improved agri- 

 cultural machines and implements. Scythestones are now used 

 in quantity only in those states or countries into which the im- 



