154 Frank Carney 



is to get rid of certain impurities that make the sand less valuable ; 

 among these are clayey materials most of which may be washed 

 away. In screening, the sand is often graded in accordance with 

 different meshes; some of the plants market, as a by-product, the 

 coarse material which makes fair ballast for roadways, or good 

 gravel for concrete work. The sand from many of the cjuarries in 

 the central part of the state contains iron, which makes it impos- 

 sible to manufacture a light-colored glass. The product of these 

 quarries is usually taken by factories that produce amber and 

 green bottles. As a whole, the glass sand quarries of Ohio do 

 not furnish raw material for the better grades of glass. 



OTHER SANDS 



Molding sand. Foundries use this sand in making molds for 

 castings. The essential qualities of such a sand are: (1) It must 

 be sufficiently aluminous to hold its shape when patterned to 

 form a mold, as sometimes the patterns are delicate. (2) It must 

 be refractory, otherwise the molten iron would fuse and spoil the 

 mold. This requires a high percentage of silica in the molding 

 sand, as ciuartz does not melt at such temperatures as will keep 

 iron in a molten condition. (3) The molding sand must be coarse 

 enough to allow gas to escape, but at the same time it must 

 hold the molten iron in shape; and it should not contain much 

 clay. 



Many surface deposits in Ohio furnish excellent molding sands. 

 Only New York and Pennsylvania produced more than Ohio 

 in 1908. 



Building sands. In the production of this sand, Ohio ranked 

 fourth in 1908. It not only provides all used within the state, 

 but ships to adjacent territory. Here again is a natural product, 

 the marketing of which depends a great deal upon building 

 trades. Where population is sparse, this sand would not be in 

 demand. In the parts of the country where population is dense, 

 and there is activity in building, great quantities of sand are 

 called for. 



Engine sand. In recent years the demand for this sand has 

 been increasing. Formerly it was used only on those parts of 

 railways and street car lines involving grades. The sand is 

 sprinkled on the rail, thus increasing the friction surface and 



