Nomographs

Have you ever made a nomograph?  Probably if you are under 50, then the answer is 'No'.  I had not made one, although before the personal computer age I did use them quite a bit.  In the early days of computing mainframes were used to produce nomographs to allow engineers to easily produce designs without hand calculations or resorting to writing programs themselves for the mainframe. (Punchcards anyone?  Actually it is ironic and fitting that my spell checker doesn't have the word, 'punchcard'!)  

Thornhill-Craver Gas Lift Choke Sizing Nomograph

I think I should make it clear that I didn't design the nomograph.  That was the task of someone long ago, but it did remind me how arcane that knowledge is.  Just to reverse-engineer the nomograph given the equation was a challenge.  At least I was able to update it with metric units and make clean copies for the gas lift class materials.  The old scans were not easy to read.