MINERAL RESOURCES OF THE STATE OF NEW YORK 6l 



working tests are necessary to establish the value of the shales of 

 any particular locality. The existence of these resources in the 

 southern section of the State may prove of greater importance in 

 the future than in the past; they seem to be the most available 

 local material for road construction as there is a dearth of good stone 

 in that region. 



The shales in some places are worked up alone, having sufficient 

 plasticity when ground to make brick. When this quality is lacking 

 a certain proportion of plastic clay is admixed with the shale. The 

 following description of the methods in current use has been taken 

 from an article by R. W. Jones in the Mining and Quarry Industry 

 for 1913 : 



" In nearly all cases the material receives a preliminary crushing 

 in jaw or gyratory crushers before it is sent to the dry pan. It is 

 reduced in the dry pan to a size that will pass a 3-16 inch mesh, 

 then screened and the oversize returned to the pan for further 

 grinding. The pulverized material then goes to the storage bins. 

 The dry pan consists of a revolving slotted or perforated iron plate 

 having a rim about one foot in height arotuid the side. Two heavy 

 iron muUers resting on edge, revolving by friction against the bottom 

 plate, crush the material. 



" From the storage bins the pulverized material goes to the pug 

 mill where the necessary water is added to form a stiff mud. The 

 pug mill consists of a semicylindrical, horizontal trough of metal 

 through the center of which revolves a shaft, furnished with steel 

 arms so set as to mix thoroughly the dry material and water and 

 to feed it continually forward to the brick machine. 



" The brick machine, generally known as the auger machine, 

 consists of a heavy tapering steel barrel set directly under the pug 

 mill or combined with the pug mill on a single base. The material 

 from the pug mill is forced by the auger under great pressure through 

 this tapering barrel and issues from a die at the end in a solid column, 

 the size depending upon the method to be used in cutting. With 

 side-cut bricks the column has a cross section of about 4^ by 10 

 inches and with end-cut bricks 4 by 4^ inches. The column 

 of stiff mud is forced along over a cutting table where it is cut by 

 means of piano wire into bricks of such dimensions that, allowing 

 for repressing, drying and burning, will produce a finished product 

 of a standard size. Twelve bricks are usually made at one cut. 

 From the cutting table the product is taken by a continuous belt 

 either to the represses or direct to the double-deck cars preparatory 



