PREFACE v 



work, rather than added at its close. This adjustment must, of 

 course, be left to the individual instructor. 



In addition to the map work it is hardly necessary to emphasize 

 the fact that field work is indispensable to the greatest efficiency. 

 Specific directions for field work, however, even if they were needed, 

 are impracticable, since local fields vary so widely. 



UNIVERSITY OF CHICAGO, 

 May 15, 1909. 



