Jinks

My current dead-tree book is Mapmatics: How We Navigate the World Through Numbers by Paulina Rowińska. There's a fada on the ń because the author was born and works in Warsaw, although her PhD is from Imperial College London.  It's a book for those who can reliably spell retroazimuthal projection but can't remember how to make one . . . even in theory. The malevolant sprite in cartography is that the world is a tangerine oblate spheroid . . . but maps are flat - so they can be hung on walls; included in atlases; or folded up a stuffed in a rucksack.

The borders of Colorado were agreed and defined by the US Congress on 28 Feb 1861 [p.172] (with a great sweeping gesture on a desk in DC) as a box between 37° and 41° N and 25° and 32° W [from Washington!]. Surveyors were sent west with theodolites, chains and compasses to put pegs in the ground and much later more geopolitical clutter [see below], like, manifest Colorado's destiny. 

But, as Rowińska points out, those 1861 congressional straight lines are difficult to reconcile with the dirt those surveyor's boots were planted in. So on maps at the finest practicable detail, Colorado is a polygon with 697 sides. Where the Colorado border changes from meeting New Mexico to meeting Oklahoma, for example, the surveyors swooped South 150m over 1,000m to keep to the 37°parallel.

A details-chap like me will inevitably load up GooMaps and track East to see if there are any more CO=OK jinks in the line. One oddity is that there is a clear dark line on the GooMap which is parallel to, but 20m South of the neat artificial dotted line that is marked for/as the borrrder. When you get to 36°59'42.2"N 102°39'35.9"W that dark line steps 2m South and then carries on East [see Top pic]. I'm guessing that is a fence line defining a ranch which in wholly within Oklahoma and needs to be accurate because good fences make good neighbours. Where US-385 leaves Baca Co, CO, the GooMaps state line is definitely not consonant with the change in the quality of the tarmac. 

Rowińska doesn't clarify that the Westings of Colorado are from Washington (nor does Congress specify where in DC is the start point). If we take those measures from the Greenwich meridian, The Colorado rectangle almost exactly comprehends the entire Azorean archipelago 36.5°–40° N & 24.5°–31.5° W. If aliens set their landing coordinates on Greenwich (as intergalactic visitors might) they'd find that "Colorado" was unexpectedly a) flat and b) plooosh!

20 pages further on in Mapmatics, another geopolitical qualification might help. In a chapter on the coastline of the Alaska panhandle and its borrrder with Canada, it is asserted that Alaska and Russia are separated by 55 mi = 89 km of the Bering Sea between The Seward Peninsula and Чуко́тский полуо́стров = the Chukchi Peninsula. Maybe so, but the political border is much much closer (4km) passing through the Diomede Islands.

There's lots more in Mapmatics. I'm not much better informed on the four-color map theorem [bloboprev] by Chapter 5 How to Simplify a Map. But I learned something new about Gerrymandering [bloboprev], not least that the original Gerry started his name with a hard G. And if you're a fan of Numb3rs [we are] Chapter 7 has some interesting background on finding serial killers with math. Recommended; there are not too many graphs and maps, so could be done as an ear-book. Yes it exists in that medium: not in Irish Libraries yet, though.