If you read enough sci-fi from the late 40’s/early 50’s, you’ll come across references to technologies then in use but which have since vanished. One such technology is the “Wire Recorder,” a way of recording sound magnetically. The basics of the technology are roughly the same as used on tape recorders, but instead of a tape of plastic film covered in iron oxide, the wire recorders used actual stainless steel wire.
The video below describes the technology and history of wire recorders and shows one in operation. The wire recorders actually worked pretty well, but they fell before the might of tape recorders. Why? Two basic reasons. First, magnetic tape recorders were capable of producing far better sound. Second, an hour of wire was nearly a mile and a half of wire. There is a sequence in the video showing the results of something going wrong during rewinding and, man, you do *not* want to have to try to straighten out that mess.