2 Introductory 
the present book has been written. Naturally the book 
does not bring much, if any, new knowledge; it is mainly a 
compilation of the well-known facts which bear upon the 
subject, selected, however, with the experience of a lifetime 
spent in the study of trees. 
Believing that only a knowledge of relationships, prin- 
ciples and reasons enables one to apply prescriptions intel- 
ligently, and that a knowledge of the nature of trees is 
necessary in order to care for them properly, it has been 
the endeavor to broaden in this direction, without, how- 
ever, becoming too technical. Technical language has been 
employed as little as possible and technical minutiz, which, 
though interesting and valuable, may in the ordinary routine 
be dispensed with, have been as much as possible avoided. 
The attempt to make the relationships clear to laymen 
has necessitated their presentation from various points of 
view in the different chapters, and this has led to repeti- 
tions; but, while such repetitions may be censured by the 
literary critic, the author believes that they serve the useful 
purpose of impressing the essentials upon the reader, and 
of making him familiar with the subject. 
The care of shade and ornamental trees is an entirely 
different matter from the care of forests. It is unfortunate 
that the distinction has not always been clearly perceived. 
The object of forestry is the substance of the tree: only 
when the tree is cut and its wood utilized, is the object of 
the forester attained: he grows trees, mot to be preserved, 
but to be harvested. Hence to call the tree-wardens of 
towns and cities ‘‘foresters’’ is a misnomer. The tree that 
satisfies the forester is most unsatisfactory to the landscape 
gardener or street tree planter, and vice versa. The latter 
arboriculturists are after shade or beauty of form, hence 
their treatment of trees is entirely different from that of the 
