498 



CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 



No. 13666. 



No. 13670. 



13666. THERMOMETERS, Recording, with clock movement for revolving the chart, and a steel coil 



spring for actuating the recording pen arm; a flexible connecting tube through which the ac- 

 tion of the mercury in expanding or contracting is transmitted from the sensitive element 

 (the bulb) to the coil spring; and a bulb or sensitive element which is inserted at the point 

 whose temperature is to be determined. The spring, the steel connecting tube, and the bulb 

 are welded together, forming a hermetically sealed mercury filled system. In black enameled 

 iron case, with nickel-plated ring, complete with 100 charts divided for making one revolution 

 in seven days, extremely sensitive bulb 18 inches long, 10 feet of flexible protected capillary 

 tubing (in case a greater length of tubing is desired, state exact length in order and add 40c 

 per foot for each foot over 10) and supply of ink and pens. 



No A B C D 



Range -40 to 120F. 30 to 230F. -20 to 60C. 200 to 1000F. 



Size of subdivisions, degrees 2 5 1 10 



Each $60.00 60.00 60.00 60.00 



Note: Thermometers of other ranges will bs furnished on application; also for 24 hours instead 

 of seven days. 



13667. CHARTS for No. 13666, 8 inches in diameter, for 7 day period. 



No "... A B C D 



Per hundred 1.75 1.75 1.75 1.75 



13670. THERMOMETER, Recording, Self Contained, for obtaining continuous weekly records of 



weather, room or incubator temperatures. The case is 12 inches in diameter, finished in 

 weather-proof black, with polished bronze hinged front. Range, to 130F. in 2 divisions. 

 Complete with lock and key, one hundred 7-day charts and bottle of special recorder ink. 

 50.00 



13671. CHARTS for No. 13670 Per hundred 3.30 



13676. THERMOMETER, Recording (Thermograph). Made in America. A most accurate thermometer 

 which will not vary its standard for years. A complete record is given by a pen upon a 

 printed chart for an entire week, and by its form the exact thermometric reading can be seen 

 at any moment, as well as the varying line traced by the pen for the time preceding. The 

 charts are changed at the beginning of each week and can be retained as a record for the entire 

 year. Mechanism consists of a spiral lamina of non-rusting material, which is exposed to the 

 atmosphere at the end of the case. It is extremely sensitive and, having no levers in its con- 

 struction, is very rigid. In non-corrosive metal case with glass front and screened openings 

 on three sides about the lamina, and with storage space for charts. Range, to 100 F. in 

 2 divisions. May ordinarily be used for any range of 100 F. between 20 and + 250" by 

 means of No. 13683 Unfigured Charts. Complete with full directions for use, charts for one 

 year, pen and ink 50.00 



(For illustration of No. 13676, see page 499.) 



