Making the Perfect Record: From Inscription to Impression in Early Magnetic Recording

Smith’s Projected Design

In “Some Possible Forms of Phonograph,” he explains one use of magnetic recording could be a “purely electrical . . . recording telephone,” where people would speak into the phone, thereby vibrating a diaphragm that would convert sounds into an electric current (Smith 1888, 116). Varying in a length and intensity relative to the duration and amplitude of what was spoken into the diaphragm, the current—together with a magnetized cord—would pass through a helix. The helix would function as a recording coil, translating the current into “a series of short magnets grouped into alternate swellings and attenuations of magnetism” impressed on the passing cord (116). The cord would be wound through two parallel reels and put into motion by hand or clockwork. And it would be kept taut by a tension brake or spring pressed against one of the reels.

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