316 



CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. 



No. 7814. 



No. 7826. 



No. 7832. 



7814. HYGROMETER, Mason, for determining humidify and dewpoint. Metal scale thermometer of 

 approximate range from 10 to 120F., mounted with insulating support on a mahogany finish 

 board S 1 /"^^ inches. Glass cistern and special wick, with complete humidity tables.. . 5.50 



7815. CISTERN only for No. 7814 ........................................................... 65 



7816. THERMOMETER, Dry Bulb, for No. 7814 ............................................ 2.00 



7817. THERMOMETER, Wet Bulb, for No. 7814 ............................................ 2.00 



7820. HYGROMETER, Mason, simpler form than No. 7814. Thermometers not raised, mounted on oak 



board 8%x4 1 /fc inches. With complete humidity tables ............................. 3.00 



7821. CISTERN only for No. 7820 .......................................................... 65 



7822. THERMOMETER, Dry Bulb, for No. 7820 .............................................. 90 



7823. THERMOMETER, Wet Bulb, for No. 7820 ............................................. 90 



7826. HYGROMETER, Standard, consisting of two Standard Thermometers (like No. 13720) 



mounted on a finely polished hardwood back 17x5 inches, metal cistern with wick, and 

 certificate for each thermometer .................................................... $13.50 



7827. THERMOMETER, Dry Bulb, for No. 7826 ............................................ 5.50 



7828. THERMOMETER, Wet Bulb, for No. 7826 ............................................ 5.50 



7832. HYGROMETER (Hygrodeik), an improved form of the Mason Hygrometer. Consists of two 



thermometers, wet and dry bulbs, mounted upon the outer edge of a chart which has been 

 plotted from new and corrected tables prepared under the direction of the U. S. Weather 

 Bureau. This chart, while complicated in appearance, is very simple and obviates entirely 

 the use of tables for temperatures between 20 and 120 degrees Fahrenheit. Size of instrument 

 10x7%x3 inches. Full directions furnished with each instrument .................... 13.50 



7833. THERMOMETER, Dry Bulb, for No. 7832 ............................................ 3.50 



7834. THERMOMETER, Wet Bulb, for No. 7832 ............................................ 3.50 



7838. HYGROMETER (Hygrodeik), same as No. 7832, but with chart on German silver, reading from 



80 to 180F ...................................................................... 15.00 



7839. THERMOMETER, Dry Bulb, for No. 7838 ............................................ 3.50 



7840. THERMOMETER, Wet Bulb, for No. 7838 ............................................ 3.50 



7341. CISTERN only for Nos. 7832 and 7838 ................................................. 80 



