Phenomena of Electricity, Magnetism, and Sound,
Reading edition
AS INVOLVED IN ITS ACTION.
WITH DIRECTIONS FOR MAKING
A SPEAKING TELEPHONE. BY PROF. A. E. DOLBEAR, TUFTS COLLEGE, Author of "The Art of Projecting," etc. BOSTON: LEE & SHEPARD, PUBLISHERS.
COPYRIGHT, 1877, By A. E. Dolbear.