EXERCISE 9 

 HOW AEE MERCURY THERMOMETERS USED? 



Materials. Some common thermometers, either Fahrenheit (F.) or centigrade (C.). 



Directions. The bright material in the thermometer is mercury (or quicksilver). See how far up 

 the tube the mercury extends from the bulb. What happens if you warm the thermometer in the 

 hands or by holding it above a stove ? if you cool it ? Do you get a quick result better by warming 

 the stem or the bulb ? Why ? For what reason are thermometers always made with bulbs ? What 

 have you learned about the action of mercury when its temperature changes ? 



Additional problems. What is the temperature of your schoolroom at your desk ? at the open window ? 

 near the heating apparatus ? 



If you have a thermometer the bulb of which can be placed in your mouth, determine the temperature 

 of your body. 



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