Thanks, Tom.
Fascinating.
I confess to forgetting about my Curta of so many years ago. The account of its invention was nothing less than astounding.
Recently, while looking through some old photos of many, many, many years ago, I discovered one of yerz truly lecturing in a classroom that had an "instructional" slide rule hanging above the black board, approximately 30" X 10-12', at least. Remember?
If anyone needs to know to what devices those latter terms refer (i.e. slide rule and black board) simply send me a SASE and I'll explain!
Oh my!