20 INTRODUCTION TO GENERAL SCIENCE 



terial which seems to contract when heated, is rubber ; this 

 shortens, although its volume increases. 



While we generally notice the expansion of a body in one 

 direction only, that is, linear expansion, it must not be for- 

 gotten that a body expands in three dimensions. If we know 

 the linear expansion of a body, however, we can easily cal- 

 culate the cubical expansion, as the increase for the same 

 change in temperature is always proportional to the length. 



Not only do solids expand, but the same is true of liquids 

 and gases. The expansion of liquids and gases gives rise to 

 many phenomena which will be described in other sections. 



References : 



1. 1803 : 89. Expansion of Liquids. 



2. 1803 : 104. Expansion of Solids. 



3. 1803 : 144. Unequal Expansion of Solids. 



a. 1801 : 261-263. Expansion of Solids, Liquids, and Gases. 



6. 1802 : 294-298. Expansion Due to Heat. 



c. 1804 : 265-270. Effects of Heat Expansion. 



d. 1805 : 297-302. Expansion and its Applications. 



e. 1806 : 322-324. Applications of Expansion. 



/. 1807 : 177-178. Effects and Applications of Expansion. 



Experiment 6. Expansion Due to Heat. 



Apparatus : Glass bulb tube, flask 100 c.c., two-hole rubber 

 stopper, thermometer, glass tube 3 feet long, ring stand, 

 asbestos mat 5" X 5", lamp, two iron screw eyes, one of which 

 will just pass through the other, two pieces of wood for handles. 



a. Put bulb tube through one hole of stopper and insert in 

 flask, half filled with water; place hand on bulb. What hap- 

 pens? Warm bulb very gently with lamp. What happens? 

 Let bulb cool, and explain what takes place. 



b. Place the thermometer in one of the holes of the stopper 

 and the glass tube in the other. Fill the flask full of water 



