PREFACE 



This little book is written for the one who does 

 not know. The man who has already arrived may 

 think it hardly worth while, but I ask him to re- 

 member that the simplest questions are the ones 

 oftenest asked, and that the beginners are the ones 

 who oftenest need help. I trust no one will be- 

 grudge the excellent company of novices even so 

 small a help as that which is here most humbly 

 offered by their friend and well wisher, 



F. A. WAUGH, 

 Massachusetts Agricultural College, igi2. 



