Ee MENS ee AL OF PEVSICAL GHOGRA PENG FOR THE USE OF SCHOOLS, ACADEMIES, AND COLLEGES. BY EDWIN J. HOUSTON, A.M. PxD,, EMERITUS PROFESSOR OF PHYSICAL GEOGRAPHY AND NATURAL PHILOSOPHY IN THE CENTRAL HIGH SCHOOL OF. PHILADELPHIA; PROFESSOR OF PHYSICS IN THE FRANKLIN INSTITUTE OF THE STATE OF PENNSYLVANIA, REVISED EDITION. PHILADELPHIA: PuBLISHED BY ELDREDGE & BROTHER, No. 17 North Seventh Street. A896.