5 ms·

Reminds me of some charts used by chemical engineers in the age of slide rules. Can anyone help me remember an example?

chemeng 7y ago
Don't know if it's what you're referring to, but psychrometric charts are always fun, and any of the thermodynamics charts (Pressure-Enthalpy being an example). The best part? You say the "age of slide rules", but these are still used today.
- rckoepke 7y ago
  Not psychrometric...the ones I'm thinking of look exactly the same as this, but allow you to solve a system of equations by drawing a straight line between points on two columns, thus making the intersection of the line with the other columns your "answer" for those variables. The scales are sometimes very strange, in order to achieve this effect.
  - chemeng 7y ago
    Ah, nomogram then?
    - rckoepke 7y ago
      Living up to your name! Thank you so much.
Cybiote 7y ago
These are known as https://en.wikipedia.org/wiki/Parallel_coordinates https://en.wikipedia.org/wiki/Parallel_coordinates and are a pretty old technique. Although the wiki lists process control as one of the major users, their history has them as dormant until revived in their modern form in the 1960s, which doesn't quite match your timeline. Perhaps the discrepancy is resolved by whether parallel axes were used as a equation solving aid versus a visualization aid? They're also not outdated, you can find them in many libraries, like highcharts here: https://www.highcharts.com/docs/chart-and-series-types/parallel-coordinates-chart https://www.highcharts.com/docs/chart-and-series-types/paral... Excellent technical coverage is: Parallel Coordinates for Visualizing Multi-Dimensional Geometry, from 1987 at https://link.springer.com/chapter/10.1007/978-4-431-68057-4_3 https://link.springer.com/chapter/10.1007/978-4-431-68057-4_... Wikipedia links to this 1880 chart: https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~32803~1152181:General-summary,-showing-the-rank-o https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~3...
- rckoepke 7y ago
  The ones I'm thinking of were "nomograms" (thanks to user 'chemeng'). Visually they look like perhaps a very specific subset of "Parallel coordinate" graphs. Definitely more for calculation rather than visualization. Evidently they were popular from around 1890 to at least 1950.
  - kortex 7y ago
    They are still quite useful for predicting boiling points under reduced pressure. https://www.sigmaaldrich.com/chemistry/solvents/learning-center/nomograph.html https://www.sigmaaldrich.com/chemistry/solvents/learning-cen...

Don't know if it's what you're referring to, but psychrometric charts are always fun, and any of the thermodynamics charts (Pressure-Enthalpy being an example). The best part? You say the "age of slide rules", but these are still used today.

rckoepke 7y ago
Not psychrometric...the ones I'm thinking of look exactly the same as this, but allow you to solve a system of equations by drawing a straight line between points on two columns, thus making the intersection of the line with the other columns your "answer" for those variables. The scales are sometimes very strange, in order to achieve this effect.
- chemeng 7y ago
  Ah, nomogram then?
  - rckoepke 7y ago
    Living up to your name! Thank you so much.

Cybiote 7y ago

These are known as https://en.wikipedia.org/wiki/Parallel_coordinates https://en.wikipedia.org/wiki/Parallel_coordinates and are a pretty old technique. Although the wiki lists process control as one of the major users, their history has them as dormant until revived in their modern form in the 1960s, which doesn't quite match your timeline. Perhaps the discrepancy is resolved by whether parallel axes were used as a equation solving aid versus a visualization aid? They're also not outdated, you can find them in many libraries, like highcharts here: https://www.highcharts.com/docs/chart-and-series-types/parallel-coordinates-chart https://www.highcharts.com/docs/chart-and-series-types/paral... Excellent technical coverage is: Parallel Coordinates for Visualizing Multi-Dimensional Geometry, from 1987 at https://link.springer.com/chapter/10.1007/978-4-431-68057-4_3 https://link.springer.com/chapter/10.1007/978-4-431-68057-4_... Wikipedia links to this 1880 chart: https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~32803~1152181:General-summary,-showing-the-rank-o https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~3...

rckoepke 7y ago
The ones I'm thinking of were "nomograms" (thanks to user 'chemeng'). Visually they look like perhaps a very specific subset of "Parallel coordinate" graphs. Definitely more for calculation rather than visualization. Evidently they were popular from around 1890 to at least 1950.
- kortex 7y ago
  They are still quite useful for predicting boiling points under reduced pressure. https://www.sigmaaldrich.com/chemistry/solvents/learning-center/nomograph.html https://www.sigmaaldrich.com/chemistry/solvents/learning-cen...