CENTRAL SCIENTIFIC CO., CHICAGO. TJ. S. A. 



177 



No. 3512. 



No. 3516. 



3500. 



3502. 



3504. 

 3508. 



3510. 



3512. 



3513. 

 3516. 



GRINDER, Laboratory Ore, with Hardened Steel Mortar and Pestle, for power, for reducing ore 

 and rocks to an impalpable powder. The pestle is attached to a sliding rod held down by a 

 spring at the top, so as to produce constant pressure on the mortar, which revolves slowly in 

 the same direction as the pestle, producing a combined rolling and sliding motion similar to 

 that in hand grinding. A scraper operates to keep the ore in the center of the mortar. By 

 dropping one of the posts on the platform and raising the pestle, the mortar can be quickly 

 removed. The machine is so constructed that no oil or foreign substance can contaminate the 

 sample. Height of machine, 18 inches; diameter of mortar, 4*4 inches; power required to oper- 

 ate, 14 h. p., at a speed of 250 r. p. m.; shipping weight, 40 pounds. (For complete descrip- 

 tion see Bulletin 422, of the United States Geological Survey, "The Analysis of Silicate and 

 Carbonate Rock," by W. F. Hillebrand, page 55) ..................... .' ............ $80.00 



GRINDER, Hance Conical Plate No. 1, for hand operation, for grinding dry materials, such as 

 drugs, grains, feed, coal, etc., to any degree of fineness down to 30 mesh. Grinder only for 

 bolting to table, with 22-inch fly-wheel for hand power ............................. 50.00 



GRINDER. Hance Conical Plate No. 1, same as No. 3502, but equipped with 10x3 inch tight and 

 loose pulleys for power ............................................................ 50.00 



GRINDER, Hance Conical Plate No. 2, for power, similar in construction to No. 3502, but much 

 larger, with 14-inch grinding plates: mounted on substantial wooden support. Height over 

 all, 48 inches; floor space, 18x31 inches; speed, 200 r. p. m.; power required to operate, 5 h. p.; 

 size of pulleys, 12x4 inches; shipping weight, 385 pounds ............................ 125.00 



GRINDING MILLS, Laboratory and Drug, for hand, operation, for grinding herbs, roots, grains, 

 feed and other drv substances. 

 Xo ........... ." 



Height, inches 

 Diam. of wheels, inches 

 Weight, pounds 

 Each 



GRINDING MILL, for hand operation, for bolting fb table or bench. For pulverizing hard sub- 

 stances for analysis, such as ores, bone, etc. Grinding surfaces are made of very hard mate- 

 rial. Diameter of hand wheel, 19% inches; weight complete, 25 pounds ............... 17.70 



EXTRA GRINDING PLATES for No. 3512 ................................... per set 4.00 



GRINDING AND PULVERIZING MILL, for hand operation, for soils, grains, dry bone, lime- 

 stone, rock phosphate, etc. Compact, strong, and durable. Height, 11 inches: length. 12 

 inches; width, 9 inches; dimensions of throat, 3x2 inches; diameter of handwheel, 19 inches; 

 weight complete, 47% pounds ...................................................... 10.00 



8% 

 15 

 6.30 



3 



15 



10% 

 22% 

 9.40 



5 

 17 



12% 

 36 



13.70 



17 



62 



18.80 



