TREES OF AMERICA. '41 



and cabbages every night; he was afraid 

 they would die, too." 



"But you do not know that it is partly 

 owing to the trees, that we get rain at all." 



" To the trees, Uncle Philip ! why, how can 

 that be ? rain comes from the clouds, and not 

 from the trees." 



" Very true ; but what are the clouds ?" 



" Why, they are up over our heads, Uncle 

 Philip." 



" Oh yes, I know lohere they are very weK ; 

 but I want you to tell me what they are, if you 

 can. But I suspect that you have not learned 

 that yet." 



" No, Uncle Philip ; I believe I do not know 

 lohat the clouds are." 



" Well, then, I will tell you : you know that 

 water when it is heated becomes vapour ; 

 you have seen the vapour rising from the 

 spout of the tea-kettle ; now the water all over 

 thr world is constantly giving off vapour just 

 di^ vhe water does in the kettle, and this 

 vapour is in fact nothing but water, made 

 very thin and light by the heat, and it always 

 becomes water agaiu when a great deal of it 

 gets together, and there is no heat to prevent 

 it ; when a great deal of the vapour does get 



D 



