Nomographs

[NortonDommi]

Hello Everybody,
This popped up over dinner and took me back to last century and primary school. I got to wondering if any of the alphabet people would know how to use one today.
I think I have a few for various things in a drawer somewhere and many of the old text books and machine manuals have them.

Found some of my old slide-rules while looking for something a few days ago and the missing memory cells are showing, might have to start exercising what few I have remaining. Only one person in school had a calculator and that was because his dad was an accountant and gave him his old one when he upgraded, even the teachers wee jealous. Times have changed fast.