Preface vii 



by Professor H. M. Cottrell, Superintendent of Farmers' 

 Institutes in Colorado. 



We are also indebted to other members of the College 

 Faculty, for without their help and advice this work could 

 scarcely have been completed. 



WENDELL PADDOCK. 

 O. B. WHIFFLE. 

 AGRICULTURAL COLLEGE, 

 FORT COLLINS, COLORADO. 

 June 15, 1909. 



