422 The Principles of Fruit-growing 



when the mercury remains below 20° F. for any length of time, the 

 cellar will be reduced below freezing, unless the ventilators are closed. 



We have now completed the fruit-book, having sur- 

 veyed the field. It is a field of great variety, demanding 

 many qualities on the part of the successful grower. 

 This grower should first apprehend the principles and the 

 underlying reasons, and to teach this is the prime purpose 

 of the book, while still everywhere discussing the prac- 

 tice. If the grower knows why, he will teach himself how. 



The author hopes that the grower will meet with much 

 success, and that his enjoyment in the work will be abid- 

 ing and real. 



