x PREFACE. 



method, which is based upon the work of Runge, will be found 

 generally useful. 



While the problems in Chapter XII. may prove useful, they 

 should be looked upon as chiefly suggestive; if they inspire the 

 reader to undertake other than standardized tests, they will have 

 served their purpose. 

 ITHACA, N. Y M 

 May i, 1911. 



