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Uploaded a work by John Ambrose Fleming from Retrieved 16 June 2020 from [https://books.google.com/books?id=2RRLAAAAMAAJ&pg=PA414 John Ambrose Fleming (1916) ''The Principles of Electric Wave Telegraphy and Telephony, 3rd Ed.'', Longmans, Green, & Co., London, p. 414, fig. 10] on Google Books with UploadWizard