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C H A P T E R T W E LV E Shooting Polaris By mid-August we’d finally finished the complete subdivision of our township into the square-mile sections required by Jefferson’s tidy vision of America, and we were spending the last week surveying the odd mile here and there we’d put off because they were easier, or more accessible to our single lonely road, and therefore jobs to save for when the helicopter broke down. Some of our work involved moving corners we’d planted earlier in the summer. Because this was an original survey, we marked and placed section corners as we ran line, gambling that when we hit the township boundary, or a line we’d already run perpendicular to ours, the line we were running would intersect perfectly the one we’d run a week or two before. This usually proved to be the case. But if we were off even a little, which we sometimes were, we’d have to revisit each wayward corner, and nudge it into correct alignment. Cadastral surveyors have always checked their work by closing individual sections, making sure the numbers they calculated matched the lines they ran. Although we seldom ran the lines around one section at a time, preferring, whenever possible, to run six mile lines straight from township boundary to boundary, it helped me to think of closing sections this way: run a mile, then turn ninety degrees. Run another mile, make another ninetydegree turn. Two more miles, two more right-angled turns, and if you’ve done everything right—measured perfect one-mile sides 235 236 Shooting Polaris and turned precise ninety-degree angles—your last line would intersect perfectly the flag you started from. Such precision is unattainable, of course, and surveying legislation has always allowed a margin of error—“acceptable limits of closure,” in the vernacular of the Manual of Surveying Instructions— to account for the relative inaccuracy of the equipment and the inevitable lapses in technique. When our nineteenth-century forebears ran their four miles of section boundaries and returned to their original flag, they were allowed to be off by fifty links—half a chain, more than thirty feet. By the time surveyors had been issued transits and eight-chain chains, the margin of error was twentyfive links, but no surveyor I knew was content with so sloppy a gap. Larry was pretty upset on those rare occasions when we were ten links off, and was only satisfied with something less than a five-link closure. So each night Larry would recalculate his lines, closing his sections on paper, and if he discovered a troubling closure, he’d decide whether we needed to run line again, or just shift corners enough to bring them into alignment with each other according to the tiny corrections he felt necessary, and that’s how we spent our last couple of late-August days on the Kaiparowits Plateau. The adjustments were never more than a few links, sometimes only a couple of tenths, which meant basically setting up the transit over the nearest flag, reestablishing line, and kicking the brass cap the inch or two it needed to go, then rearranging the rocks in the mound to reanchor the pipe. There was one significant difference that year. Because we were running an original survey, Larry was required to do math he’d never done before, to work those calculations necessary to make our lines compensate for the curvature of the earth. The first instructions to surveyors, those included in the legislation passed by congress in 1785, neglected to provide for the fact that we live on a spherical planet, and this flat-earth mentality resulted in some awkward moments in the field, and later in the central office. The problem was this: on one hand, parallel lines are defined by the fact that they never meet. On the other hand, survey crews twenty miles apart ran what they assumed were parallel lines that turned out to be not quite parallel. Even though they had begun running lines according to what their compasses told them was northward, because these magnetic lines converged steadily as they ran to- Shooting Polaris 237 ward the magnetic pole, their lines actually inclined toward each other, ultimately resulting in some disconcertingly trapezoidal sections , determined by not-quite-perpendicular angles. Of course, this came as no surprise to the surveyors themselves, who had studied solid as well as plane...

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