AUTHOR’S PREFACE. 
IX 
The held of nature is boundless, and her 
phenomena so multitudinous that a thousand 
volumes could not exhaust her. Every local¬ 
ity has its own studies of peculiar interest. A 
series like this can select only a small part for 
consideration. What shall guide us in choos¬ 
ing ? It is evident it must be that which is of 
general distribution and can be used in a typi¬ 
cal way. Accordingly the first three books 
treat of the flowers, birds, trees, fruits, plants, 
animals, and the phenomena of air and water, 
which are most easily accessible both in their 
environment and to the children in the school¬ 
room. 
The fourth and flfth volumes, which are to 
be read by children of greater experience, nat¬ 
urally draw more heavily on the imagination 
and present facts from other lands and zones, 
but such as the reader will appreciate, and 
such as will enable him to obtain a fair con¬ 
ception of the realm of life as it exists in vari¬ 
ous climates and conditions. The interesting 
life of the sea, the tropical life of the earth, 
and the frozen north, as well as the evidences 
of nature’s forces now operating, which have 
given us the geological history of the globe, 
receive attention in the fourth book. 
