THE MINING AND QUARRY INDUSTRY I906 43 



trimmed in the mine and loaded into the mine cars. The remaining 

 ore and enough of the overlying shale is then removed by drilling 

 horizontally and blasting, so as to give sufficient hight for the 

 miners to work. 



The ore varies from 30 to 36 inches in these mines so that about 

 18 to 24 inches of shale is removed. The waste from the ore and 

 all the shale removed goes into the gob. The roof is further secured 

 by timbering. The posts are placed parallel to the working face and 

 from 5 to 10 feet apart depending upon the nature of the roof. 



The ore is hauled from the mine workings on cars. In the Frank- 

 lin Iron Manufacturing Co.'s mines the cars are drawn by mules. In 

 the Borst mine, steel cars with roller bearings are used; the grade 

 in the mine is so slight that they can be operated by hand. In this 

 mine steel rails connected by fish plates are used. The track rests 

 directly on the rock so that in reality it serves as a portable railway. 

 In the Franklin mines ventilation is made more perfect by means of 

 a central air shaft. 



The product of the Borst mines goes principally to paint manu- 

 facturers. The ore from the Franklin mines is smelted at the com- 

 pany's furnace at Franklin Springs about 2 miles south from the 

 mines. 



MILLSTONES 



Millstones are obtained in Ulster county. The industry is a small 

 one, but it has been established for more than a century and still 

 furnishes most of the millstones made in this country. The product 

 is known as Esopus stone, Esopus being the early name for Kings- 

 ton, once the principal point of shipment. 



The millstones are quarried from the Shawangunk grit, a light 

 gray quartz conglomerate found along the Shawangunk mountain 

 from near High Falls southwest toward the Pennsylvania border. 

 The CacaHco stone obtained in Lancaster county. Pa., and the Brush 

 mountain stone, found in Montgomery county, Va., are of similar 

 character. In Ulster county the grit rests upon the eroded surface 

 of gray Hudson River shales and is overlain by red shale. It has 

 generally been correlated with the Oneida conglomerate of central 

 New York, though recent investigations have shown that it belongs 

 higher up in the series, namely in the Salina. Its thickness ranges 

 from 50 to 200 feet. 



The grit is composed of quartz pebbles of milky color inclosed in 

 a silicious matrix. The pebbles are more or less rounded and vary 

 from a fraction of an inch up to 2 inches in diameter. The texture 

 is an important factor in determining the value and particular use 

 of the finished millstones. 



