Temperature. Thermometers 159 



tube is placed under water beneath the mouth of a large jar filled with 

 water, and the vessel containing the ice is heated. What volume 

 of air at 20 will be collected in the jar if the heating be continued 

 till the flask is surrounded by boiling water ? (The volume of the 

 delivery tube may be neglected.) 



12. 1 g. of hydrogen at and 760 mm. occupies 11 -127 litres. 

 What will be its volume (a) at 132 and 800 mm. ; (6) at 132 and 

 745 mm. ? 



CHAPTER X 



HEAT AS A QUANTITY 



101. In the last chapter it was shown that a tea- 

 cupful of hot water was as hot as a kettleful when 

 neither quantity of water gave up heat to the other 

 on being mixed. When preparing a hot bath, however, 

 it would be of little service to add a teacupful of 

 boiling water to each gallon of cold water used, while 

 a bath of suitable temperature may well be prepared 

 by putting in a kettleful of boiling water for each 

 gallon of cold, supposing the kettle of average size. 

 Although the teacup and kettle contain quantities of 

 water which are equally hot, their contents do not 

 possess equal heating power, or, in other words, the 

 quantities of heat contained by the contents of the 

 two vessels are not equal. 



To test the above statement, we will perform 



EXPERIMENT 52. Pour into a beaker 100 c.c. of 



water from a measuring cylinder. Into another beaker 



measure out 500 c.c. of water and take its temperature. 



Heat the water in the first beaker, with constant 



