ΠΠ²ΡΠΎΡ: WILLIAM D. ENNIS, M.E.
ΠΠΎΠ΄: 1915Π―Π·ΡΠΊ: ΠΠ½Π³Π»ΠΈΠΉΡΠΊΠΈΠΉΠ’ΠΈΠΏ: ΠΠ½ΠΈΠ³ΠΈ
THIS book was published in the fall of 1910. It was the first new American book in its field that had appeared in twenty years.It was not only new in time, it was new in plan. The present edition,which represents a third printing, thus demands careful revision.
















ΠΠΎΠΌΠΌΠ΅Π½ΡΠ°ΡΠΈΠΈ
ΠΠΎΠΉΠ΄ΠΈΡΠ΅ ΠΈΠ»ΠΈ Π·Π°ΡΠ΅Π³ΠΈΡΡΡΠΈΡΡΠΉΡΠ΅ΡΡ, ΡΡΠΎΠ±Ρ ΠΎΡΡΠ°Π²ΠΈΡΡ ΠΊΠΎΠΌΠΌΠ΅Π½ΡΠ°ΡΠΈΠΉ