Gridding a national landscape
THE ORIGIN of the United States' land survey system has been associated with Thomas Jefferson, who chaired a committee in 1784 to prepare a plan for the government of the Western Territory. His proposal divided the land into geographical square miles by "hundreds" with lines oriented north-south and east-west, crossing each other at right angles. But there was also Hugh Williamson, Congressional delegate from North Carolina who had studied medicine in Utrecht, who in the same year suggested to the committee to divide the land by "parallels, dotts and meridians." He had seen rectangular field divisions in the Netherlands, some dating from the Roman era. One can readily call the first proposal the Jefferson-Williamson plan while acknowledging the contributions by others during the debate, notably Timothy Pickering of Massachusetts, who warned astutely against having straight lines represent converging meridians. 1
Jefferson may have been influenced by Roman centuriation and the Cartesian esprit geometrique during the century of the Enlightenment. But people in different places at different times can find the same solution to a problem. We should therefore consider the human context. Squares, circles, and equilateral triangles are more readily recalled than figures of irregular shape. The straight line, rare in nature, can be obtained by stretching a vine between two trees; with one end tied to a tree, we can with the other circumpace the ideal form of a circle. But circles are useless for subdividing an area when complete coverage is desired. In the 3rd century AD the Greek geometer Pappus of Alexandria considered the hexagon; but it lacks parallelism. The pervasive functionality of the right angle makes it the preferred form, and human eyes still see it when shown an angle of some degrees more or less than 90. This may be related to man walking erect, similar to his preference for the number 6, which equals our existential directions in space-up, down, forward, backward, left and right.