I'm probably older than most of the people here, but the slide-rules that I used for 10th grade chemistry were essentially nomographs (fortunately I had a calcu

I'm probably older than most of the people here, but the slide-rules that I used for 10th grade chemistry were essentially nomographs (fortunately I had a calculator by the time I took physics in 12th grade). I have a couple that I keep around for sentimental reasons but haven't used them in years.