liO NEW YORK: STATE MuSEUM 



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 Cacalico 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 tend to show that it belongs 

 higher up in the series, probably 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. 



In quarrying advantage is taken of the joints which intersect the 

 strata. There are usually two systems of joints, the one transverse 

 and the other longitudinal to the strike. By selection, a block of 

 approximate dimensions to make a disk of any desired size can be 

 obtained. The blocks are roughly shaped by drilling holes and 

 splitting with wedges. They are then cut to shape and undergo a 

 final tool-dressing which varies with the use to which they are to 

 be put. 



The sizes of the stones marketed range from 15 to 90 inches. 

 The greater demand is for the smaller and medium sizes, with 

 diameters of 24, 30, 36, 42 and 48 inches. A pair of 30 inch mill- 

 stones commonly sells for $15, while $50 may be paid for a single 

 stone 60 inches in diameter. The largest sizes bring from $50 to 

 $100. Besides the common type of millstones, disks are furnished 

 which are employed in a roll type of crusher known as a chaser. 

 The pavement of such crushers is also supplied by the quarrymen 

 in the forms of blocks. Quartz, feldspar and barytes are commonly 

 ground in chasers. 



Most of the Ulster county quarries are situated along the northern 

 edge of the Shawangunk mountain. Kyserike, St Josen, Granite 



