T30 



NEW YORK STATE MUSEUM 



Silica (Si0 2 ) 



Alumina (A1,0 3 ) . . . 

 Ferric oxid (Fe 2 3 ) 

 Magnesia (MgO).. . 



98.6 

 •23 



•17 

 trace 



99.00 



The output of glass sand in 1905 amounted to 9850 short tons 

 valued at $7765, reported by four producers. In the preceding year 

 three companies- reported a total of 11,080 short tons, valued at 

 $8484. 



At one time considerable quantities of glass material were obtained 

 near Ellenville, Ulster co. The Shawangunk grit, a nearly pure 

 quartz conglomerate, was quarried, ground and shipped to glass 

 companies in Pennsylvania. The Potsdam sandstone has also been 

 used for glass making. 



Molding sand. Molding sand of excellent quality is found in 

 the Hudson river valley. A large part of the requirements of 

 foundries in the eastern United States is furnished from this section. 

 The molding sand occurs in beds of varying thickness underlying 

 the soil and resting upon coarser sand or upon clay. In some cases 

 it outcrops at the surface, the usual covering having been removed 

 by erosion. The method of digging the sand is described .by F. L. 

 Nason, as follows : 



In gathering the sand for market a section of land i or 2 rods in 

 width is stripped of its overlying soil and down to the sand. The 

 sand is then dug up and carted away from this strip. After the 

 sand is moved from the first strip, a second belt is cleared of soil 

 and dumped on the first and so on until the whole field has been 

 stripped of its sand. After stripping the entire field the soil is 

 replaced and leveled down and is then just as good for agricultural 

 purposes as before. 



It is estimated that 6 inches of sand will yield 1000 tons an acre. 

 The owner of the land receives on the average about $2.50 an acre 

 as royalty for removing the deposit. 



In Albany county the finest grades of molding sand, adapted for 

 stove and other castings that require a smooth finish, are obtained 

 at Delmar and Selkirk. The output is shipped to Albany, Troy and 

 ..more distant points, bearing a freight rate as high as $3 a ton. 

 Deposits are also worked near Coxsackie Station, Columbia co. and 

 near Camelot and New Hamburg, Dutchess co. 



