>A branch of mathematics in which methods of graphical representation of functional dependencies are studied. The resulting designs are called nomograms. Every nomogram is constructed for a definite functional dependence within specific limits of variation of the variables. In nomography computational work is replaced by the performance of the simplest geometric operations indicated in the instructions and an evaluation of the answers.
>The accuracy of answers by nomography depends on the form of the nomographic presentation of the dependency, the limits of variation of the variables, the dimension of the design, and on the chosen type of nomogram. On the average, nomograms can provide answers to 2–3 true digits. When the accuracy of nomograms is insufficient, they can be used for provisional calculations, for finding zero-order approximations, and for the control of computations with the aim of discovering gross errors.
>Nomograms can also be used to study functional dependencies, putting the nomograms at their foundation. Often such a study can be carried out by nomograms in a considerably simpler and more intuitive way than by other methods. By means of nomograms one can investigate the influence of various variables on the required variable, give an intuitive interpretation of some previously known properties of the dependency in question, and establish previously unknown peculiarities of it. Nomographic methods of investigation can be applied, for example, in problems on the selection of parameters in empirical formulas on the results of observations, in the approximation of one function by another, and for finding extremal values of functions.
If you like Nomograms or other mechanical mathematical curiosities, do check out @ChrisStaecker on YouTube. He does short, funny reviews/how-to videos for his collection of nomograms, measuring tools, mechanical and paper calculators.
Unfortunately his channel also mixes his university lectures, so you have to check out his playlist [0].
Here's a nomogram for solving a quadratic equation. Check out the O-riginal video on YT! [1]
I don't have the image at hand but the most impressive nomogram (?) I've seen was in a pilot's operating handbook for some version of the DC-3.
It allows you to calculate take-off ground run distance as a function of no less than four variables! Namely,
- gross weight,
- altitude,
- headwind, and
- softness of ground surface.
The same POH also had two more useful (but simpler) nomograms:
- density altitude as a function of temperature and altitude, and
- rate of climb as a function of density altitude and gross weight.
The reason I remember these two is not that they were particularly cool on their own, but because they were placed side-by-side in the POH so you could also think of them as a single nomogram that let you compute rate of climb as a function of temperature, altitude, and gross weight.
In the Pixar movie "Lightyear", at some point we see Buzz using an E6B calculator to quickly calculate a trajectory correction in space.
The E6B is some kind of nomogram/slide rule hybrid, still widely in use by pilots in flight training for dead reckoning.
Funny fact, the chart that Buzz uses in the film is used to calculate wind correction...in space. (Well he does get 'pushed' off course by the wind of an explosion).
Wonder why the art was "lost" (maybe between 2008 and now, as the title does not contain th word)? I guess it is true that with computer program one does not have to rely an books. However, looking at the civil engineering books of my wife, which a full of nomograms, I would not consider it lost. I guess they follow a similar fate as logarithmic tables.
In the meantime I think we can change the URL to https://deadreckonings.files.wordpress.com/2008/01/nomograph..., which has an earlier version of the same piece.