@tubetime
With the spinning drum, spark paper and whatnot, it was really reminding me of hardware demonstrated off in Tim Hunkin's 'Secret Life of the Fax Machine'.

Which he then promptly, specifically mentioned - complete with link. Hah.

Anyhow, that link to the newly digitised version of a programme I first watched aged 13 or so, when first broadcast...

youtube.com/watch?v=yuUyt9RG7p