344 APPENDIX 



period will be required to complete the work successfully. It will, 

 therefore, be necessary for the teacher to have all material at hand 

 to start the work promptly at the beginning of the period. The 

 instructor should plan for each laboratory period far in advance. 

 This is absolutely necessary in the case of Ex. 16, 17, 18, 58, and 59, 

 for which material must be prepared four weeks in advance of the 

 class period. 



