Flat(ter) here referring to the Earth as an ellipsoid, not an actual flat thing, in case people were wondering. Really enjoyed reading this, hadn't even realised how complex the political and technical practicalities of measuring the Earth were in the early 19thC.

Also, a much easier read than Pynchon's Mason and Dixon [0]

[0] https://en.wikipedia.org/wiki/Mason_%26_Dixon