468 NATURE STUDY. 



i 



Eepeat experiment, putting in a tin cup a small quantity 

 of water, which the children have measured in a bottle, 

 heat for a time, observing as before, and have children 

 measure again. 



Clinch the observation and thought. " The water goes 

 away." 



Step II. What makes the water go away ? Repeat one 

 or both experiments, extinguishing the flame, and relighting 

 it two or three times, that the children may see that " the 

 water stops making bubbles " when the fire is blown out, 

 and begins again when the fire is lighted. At this stage 

 the children can probably only see that the fire or flame 

 " makes the water go away." They may not be ready for 

 the generalization ( which must be based on many observa- 

 tions to mean much). " Heat makes the water go away." 



Step III. What becomes of the water ? Boil water in 

 tin cup. Children, if really observing, will see the 

 " smoke " ( as they are apt to call it) or " steam " coming 

 from the boiling water. Invert funnel over cup. The 

 " steam " can be seen much more clearly coming from nar- 

 rowed opening of funnel. They may state that the water 

 makes or turns into "steam." Hold a dry tumbler or a 

 slate or plate over the open cup, and later over the inverted 

 funnel. What gathers on the inner or lower surface ? 

 Make sure that the children see the minute drops of water. 

 Impress idea that what they call " steam " is made up of 

 little drops of water. 



Show the children how a piece of chalk can be broken 

 into smaller and smaller pieces until it becomes as fine as 

 the chalk dust below the blackboard. So heat or fire breaks 

 up water first into bubbles, then into smaller and smaller 

 drops. This can be shown by heating the dry tin lid, and 

 pouring a few drops of water on it, letting the children see 

 how the water breaks into little drops, which dance about 



