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



305 



No. 7498. 



No. 7498. 



Nos. 7508-9. 



7498. HARDNESS TESTEE. Scleroscope, Shore's, for determining the comparative hardness of metals. 

 The method consists in dropping a small hammer from a fixed height upon the piece being 

 tested, and measuring the height of the rebound upon the scale, which reads directly in de- 

 grees of hardness. Complete with Scleroscope, plastermount vessel, stand with swinging 

 arm, magnifier, hammer for soft metals, one each brass and hard steel, calibrated reference 

 bars, and 50 blank curve charts in polished wood carrying case. Descriptive booklet sent 



upon request $170.00 



HARDNESS SCALE, see Blowpipe Apparatus. 



7500. HATCHET, high grade steel, black finish, polished face and bevel, selected white hickory handle, 



3% inch bit 1.25 



HEAT GAGES, see Pyrometers. 



HEATEES, Electric, for Extraction Apparatus, see Extraction Apparatus Heaters, Nos. 5260 to 



HEATERS. Electric, for ether extractions, Kjeldahl digestions, etc. Consists of six electric hot 

 plates. 3^ inches in diameter, mounted on a sheet iron box. Each heater has its own switch, 

 enabling any number to be used at a time. Lenth, 24 inches; width, 5*4 inches; height, 9 

 inches. Complete with rack for Kjeldahl flasks, and with connecting cord and plug. 



7508. 

 7509. 



No 



Number of hot plates. 



Length, inches 



For 110 volts 



For 220 volts. . 



A 



6 



24 



57.75 

 57.75 



B 



10 

 40 



90.75 

 90.75 



7512. HEATER, Cenco Electric, for Volatile Fluids, designed by W. H. Ross, consisting of a box 

 80x20x12 cm of asbestos board containing a system of resistance coils, above which is sup- 

 ported a sheet iron pan. The top of the outer box is removable and has openings for flasks 

 which rest on the bottom of the iron pan below. A switch arrangement permits the use of 

 currents of from 1 to 4 amperes at 110 volts, the change from minimum to maximum being 

 made in nine steps if desired. With top removed, the heater becomes an ordinary hot plate. 

 By placing a liquid in the iron box the heater becomes a liquid bath. Complete with covers 

 for holes . , 37.50 



