The telephone, the microphone & the phonograph

“The telephone, the microphone & the phonograph” by Th., comte Du Moncel — a free Project Gutenberg ebook, available to read as an EPUB on BookMarket. Subjects: Microphone; Phonograph; Telephone. Original source: https://www.gutenberg.org/ebooks/75683. This ebook is in the public domain in the United States; the Project Gutenberg eBook license applies to the original text.