Errors in this brief history of sound recording

[coyote]

How they made Ampex tape recorders

From a 1950 film on Ampex tape machines. The wording makes it sound like all the earliest discs were thick like the Diamond Disc pictured. I suppose even as early as the 50s people were susceptible to "If it says "Edison," it's got to be early!"

[edisonplayer]

The early double sided Columbias were thick,as well as the Victor Monarchs.edisonplayer.