The telephone: an account of the phenomena of electricity, magnetism, and sound, as involved in its action
An 1877 popular-science explanation of the telephone by Amos Emerson Dolbear, published in Boston by Lee & Shepard for general readers curious about electricity, magnetism, and sound. The eighteen figures are small white-line diagrams reversed out of coarse black grounds: horseshoe magnets wrapped in coils, trailing wires, sectioned resonance boxes, lettered parts, and a tuning fork beside banded vibration traces.
