A Straight Line Between Two Points

from the journal of
Henry David Thoreau:

December 17, 1856/

Yesterday afternoon I was running a line through the woods. How many days have I spent thus, sighting my way in direct lines through dense woods, through cat-briar and viburnum in New Jersey, through shrub oak in New England, requiring my axeman to shear off twigs and bushes and dead limbs and masses of withered leaves that obstruct the view, and then set up a freshly barked stake exactly on the line; looking at these barked stakes from far and near as if I loved them; not knowing where I shall come out; my duty then and there perhaps merely to locate a straight line between two points.

Bright Angel Canyon at twilight (top)
inside Seventyfive Mile Canyon (middle)
looking downriver from Mineral Canyon (below)