Monday, January 08, 2018

The Strange Beauty of Grid Corrections

Before Thomas Jefferson became president he came up with the bright idea of dividing up the American west into regular rectangular parcels of land. The Public Land Survey System was devised in order to distribute land to Revolutionary War soldiers and to make it easier for the government to raise money by selling land.

The result is what is now known as the 'Jefferson Grid'. If you have ever flown over the United States then you will no doubt have seen these square mile sections in the American landscape. From the air it appears that a lot of the USA is almost perfectly divided into one mile squares.

Although it isn't quite perfect. If you've ever driven across that same landscape then you might have also experienced Jefferson Grid corrections. In order to correct for the curvature of the Earth the regular Jefferson Grid system has to make occasional deviations. These deviations help get around the problem of placing a two dimensional rectilinear grid onto the surface of a three dimensional sphere.

Photographer Gerco de Ruitjer's has compiled a beautiful collection of aerial images showing examples of where the Jefferson Grid has strange kinks, bends or curves to correct for the curvature of the Earth. In Grid Corrections you can view examples of where the Jefferson grids are not perfectly aligned.

If these grid corrections are not to your taste then you might prefer to view areas where the grid is perfectly aligned. You can see some great examples of how Thomas Jefferson shaped the American landscape on the Jefferson Grid Instagram account. This account posts aerial imagery (taken from Google Earth) showing examples of Jefferson's gridded plots of land.

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