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, PROFESSOR OF PHYSICS 

 IN THE FRANKLIN INSTITUTE OF THE STATE OF PENNSYLVANIA, PRO- 

 FESSOR OF NATURAL PHILOSOPHY AND PHYSICAL GEOGRAPHY IN 

 THE CENTRAL HIGH SCHOOL OF PHILADELPHIA, ETC., ETC. 



PHILADELPHIA: 



J. B. LIPPINCOTT COMPANY. 

 1893. 



