The blog of

Mon Nov 13, 2023 13 Projections for 2023 (Part 11)

A collection of projections for political world maps
(see Intro for further explanations)

November: Cahill-Concialdi

Creator Luca Concialdi (2015)
Group Polyhedral
Property Conformal
Other Names
Remarks Inspired by the butterfly map by Bernard J. S. Cahill (1903). More information in my blog.

Shortly before the end of the year, we see another conformal projection – the last one we had was the Mercator projection on the cover – but one of an unusual kind. At least in terms of the outer shape of the map, because as far as the proportions of the continents are concerned, it performs better than many other conformal projections, and certainly better than the Mercator.

The lines are shown at areal inflation values of:
  1.2,   1.5,   2.0,   2.5,   3.0,   and 3.5.

I’ve said more than once that some people feel that world maps should be equal-area for reasons of equitability. And I’m definitely not saying that this is wrong – but still, I have also stated before: “if I was a continent, I’d be displeased by cruel distortions just as much as I’d be by undue diminishment”. So if you’re going for equitability, a conformal political map may not be that wrong after all.

Well, yes, Brazil is significantly enlarged, just like a few West and East African countries, but the nation that probably gets most out of it, is the Solomon Islands, and who wouldn’t grant them that?

So, how does the OGABO version do?

As much as I like the Cahill-Concialdi, I can’t recommend it in this version – although I’m of the opinion that orientation is not even difficult on a map like this. But of course, Alaska and the Chukchi Peninsula, for example, or Tierra del Fuego and South Africa seem far too far apart. I think interrupted projections should generally not be used without showing the boundary lines of the map.

The projection of December will look quite ordinary again. And it won’t just be the last projection of the year – it will also be the last projection in my calendar series. After eight calendars and four years of writing about them, I’m simply not in the mood for another one.

My 2023 Map Projection Calendar

To read another part of my 2023 map projection calendar series, select the desired month.


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Cahill Butterfly, Cahill-Keyes, Cahill-Concialdi -- all my favorites! Thanks for the attention :-)
Mon Jan 01, 2024 5:00 am CET
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