This is fascinating. I'm a programmer, and somewhat familiar with digital circuits. I'd never really understood how someone would go about constructing an analog computer. This is it, bang on. Resistors for linear changes, capacitors for exponential curves. Pretty neat, an array of meters coupled with a bunch of analog components would solve (approximately) really complicated stuff.<p>It's also pretty neat you can get an approximate solution in a single step, rather than cranking through a bunch of operations. It seems like a compression problem in information theory, especially when you consider the two step or multi step graphs.
I upvoted this article because it is really interesting, but unfortunately I disagree that nomography can be relevant today. It is forgotten so easily because its not worth the effort with the availability of computers. Computers aren't hard to use and to learn how to use. Try doing through the exhaustion of doing numerical calculations for a day with a slide rule and nomograms to see why.
Nomographs are often used in airplane manuals. When your power plant dies, you still want to be able to calculate your range based on speed, altitude etc.
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.
I'm a CBRNE specialist, and we use these for estimating yield of nuclear detonations based on various paramaters (flash-to-bang time, angular width of cloud top, etc.)
I'm surprised the author didn't mention the Smith chart: <a href="http://en.wikipedia.org/wiki/Smith_chart" rel="nofollow">http://en.wikipedia.org/wiki/Smith_chart</a>
Meta-comment: I know I saw something about this before, but why is it that any PDF gets a [scribd] tag, even when it has nothing to do with scribd.com? It doesn't make any sense.