POR6 STRT HOUSTON o OUTLINES OF FORESTRY; OR, THE ELEMENTARY PRINCIPLES UNDERLYING THE SCIENCE OF FORESTRY. BEING A SERIES OF PRIMERS OF FORESTRY. BY EDWIN J. HOUSTON, A.M., MEMBER OF THE PENNSYLVANIA FORESTRY ASSOCIATION, PROFESSOROFPHYSICS IN THE FRANKLIN INSTITUTE OF THE STATE OF PENNSYLVANIA, PRO- FESSOR OF NATURAL PHILOSOPHY AND PHYSICAL GEOGRAPHY IN THECENTRALHIGHSCHOOLOFPHILADELPHIA,ETC.,ETC. PHILADELPHIA: B. LIPPINCOTT COMPANY. J. 1893. COPYRIGHT, 1893, BY J. B. LIPPINCOTT COMPANY. Main r GUv- Agric. PRINTED BY J. B. LIPPINCOTT COMPANY, PHILADELPHIA. PREFACE. WHEN from any cause a necessity exists in any country for the removal of its forests from ex- tended areas, unless care be taken as to the man- ner in which such removal is made, and some parts are left wooded, irreparable injuries will inevitably follow. In the United States, where the enormous in- crease in population has resulted in the removal of the forests from extended areas, such intelli- gence and care have unfortunately, in most cases, not been exercised. The timber lands have gen- erally been purchased at figures based almost entirely on the value of the standing wood. The trees have been cut down in a reckless manner, and fires, carelessly started, have often been left indifferently to burn themselves out. No attempts have been made to protect the soil that has been denuded of its natural protective covering by the axe or the fire. Before the forest has been made to yield its entire harvest, the greed of the 3 4 I -'.v'rV '{ tJfBJQ^Efii speculator has too often led him to abandon to the destructive action of the elements the area he has thus despoiled, in order to seek another, as yet unbroken, forest area. Instead of carefully removing some of the trees from the forest, and leaving the area in such a condition as to enable it to produce a new growth, in the United States it has too frequently been the case that the virgin forest is thoughtlessly attacked, its best trees cut down in so careless a manner that the harvested crop amounts to, per- haps, but a third, or even less, of the total growth, and the remaining part abandoned to certain destruction by the elements. The irreparable loss caused bysuch greed should be prevented by the enactment ofjudicious penal laws. It is often very difficult to persuade the general public that evil results following any course of action, which do not come immediately, are not thereby prevented from coming eventually. Be- cause the evil day draws not nigh quickly, there is a tendency to believe that it will never come at all. An attempt has been made in the " Outlines of Forestry" to point out to the general public, in PREFACE. 5 simple, non-technical language, the character of the effects, both on the general climate of a coun- try and on the distribution of its rainfall, which inexorably follow the unsystematic removal of its forests. It is only necessaryto give the public some little insight into the effects produced bythe destruction of the forest to arouse it to a conviction of the necessity for the existence of "Forestry Associa- tions," for the enactment of laws regulating the manner in which the forests shall be removed, and for the setting aside of certain districts on which forests shall be perpetually maintained. In order to enable the readers of this little book to carry their reading beyond the elementary prin- cipleswhich it discloses,appropriate extracts,taken from standard authors, and published by permis- sion of the authors or publishers, have been added at the end of each primer. In all cases the exact title of the book has been given, as well as the names of its publishers. For general aid in remembering the princi- ples discussed in each primer, a concise review has been given at the close of the book in the form of a primer of primers. The author has not hesitated to consult freely 1* 6 PREFACE. all standard authorities in matters pertaining to the general subject of forestry. There have been added to the book,in the shape of an appendix, lists of trees suitable for planting in different sections of the United States, as fur- nished by eminent authorities on the subject. The author desires to express his thanks to the gentlemen who have responded to his circular letter of inquiry as to lists of trees suitable for replanting in various sections ofthe United States, and to his friend Professor Charles S. Dolley for revision of the manuscript of this book. EDWIN J. HOUSTON. CENTRAL HIGH SCHOOL, PHILADELPHIA, PA., January, 1893.