Shucks, it's only a letter out Richard! You were within 1/26th after all.
This thread reminds me of a tale one of my uncles used to relate. He was (still is, going strong-ish at 90) a mechanical & electrical engineer, who could fix most things (especially after being grabbed by the REME - Royal Electrical and Mechanical Engineers for those not familiar) when doing his National Service.
He drifted into early CAD development work and ended up doing what were quite clever things in one of those clever places outside Cambridge back in the 1970s and 80s. A clean sort of job that didn't need overalls, just a jacket and grubby tie, biros various and log tables and pages of Zeus sticking out of the pockets, sort of thing.
Anyway, one of his responsibilities was to help with hiring new technical people, often engineering graduates.
His standard question to any aspiring applicant was 'Please describe for me how a typical sewing machine works'. Perhaps it was a common question to ask back then (?), dunno, but he says that it sorted the sheep from the goats in a nano-second.
So I've snaffled your pic GB, and will try to put one over on him next time I see him. (But I suspect he'll tell me straight off what it is, and then explain how it works. When we all wake up from that, there'll be a beer. Some habits die hard.)
