— 12— 



halves, that these again divide and so on till the divisions become so 

 small that they can no longer be seen. Ot course the full significance 

 of this fact one would not attempt to teach here, but it is well worth 

 seeing as a fact. Then every step of formation of body, head, limbs, 

 tail, etc., may be noted as the process progresses. 



Insects. 



Insect's eggs and cocoons as they may be found can be placed in 

 bottles and jars with netting tied over them to retain the hatched out 

 insect when it appears. Date these and examine from time to time to 

 detect time and progress of development. 



It is well to have some one, or a small group of children to take charge 

 of and care for all such jars, etc. 



Lessons with Non=living Objects. 



HEAT EXPANDS WATER. 



Fill a flask or a bottle with water. Close with a cork through which 

 a glass tube passes. A short tube will answer, but if two or three feet 

 long it will be better. 



To start with, have sufficient water in the flask to extend up into the 

 tube two or three inches. Be sure to have no air in with the water. 

 Allow members of the class to fill and arrange the apparatus. Let all 

 fee clearly just how everything is arranged. 



Place the flask on the stove, or over an alcohol lamp, and have the 

 class observe the result, and, if they can do so, explain why the water 

 rises. If the simple explanation that the heat makes the water larger 

 (expands it), is not given, do not give it but allow them more time to 

 think on the matter. If wrong explanations are oflFered, do not imme- 

 diately neglect them but ask for proofs, or devise experiments which 

 disprove the oflFered explanation. For example, if a child insists that 

 the water rises in the tube "because heated water is lighter and goes 

 up," place the apparatus so that it extends in a horizontal position and 

 repeat the experiment. 



The above may occupy the time of more than one lesson. It ought 

 not to be hurriedly passed over. In subsequent lessons it may be pro- 

 posed to experiment with other liquids. Allow the children to select 

 the liquids, arrange the apparatus, and try the experiments as far as 

 possible. The eflFect of cold may be studied also. 



When a few liquids are thus experimented with and comparisons 

 made between them, the thermometer may be introduced. It is to be 

 seen as a small flask filled with mercury, or with colored alcohol. 



A number of simple experiments can be devised with the thermom- 

 eter, which will make clear its use in determining the temperature of 

 things. 



In all experiments give as much chance as possible for each one to 



