420 ILLINOIS STATE ACADEMY OF SCIENCE 



year. There is an incentive to work because the pupil 

 has chosen a problem which appeals to him. The earnest- 

 ness and enthusiasm shown is gratifying. 



Much might be written on the use of any of the above 

 devices. There is no claim for anything original. But 

 if this rambling paper has brought back to the mind of 

 anyone here something which may be of use, it will have 

 accomplished its purpose. 



