in reply to My preferred temperature scale is:
I pre-marked my slide rule at key points to make Celsius to Rankine conversions easier.
"I pre-marked my slide rule..."
Wow! Seems like it's still in use.
BTW, I bought one by Faber-Castell a while ago - with it's original packaging and manual. And i inherited another from my father with a teakwood core (!) for mercantile application ditto from Faber.
Please see also this as well as Albert Nestler and Don't know what a slide rule is for ;-)
Best regards, Karl
«The Crux of the Biscuit is the Apostrophe»