I recently read of a Swiss physicist named Horace Benedict de Saussure who, living in the 1700s, wanted to measure the intensity of blue in the sky. He created the cyanometer, a round dial that had 53 shades of blue, moving from white through a range of blue to black. I find this to be at once beautiful and troubling. I, too, want to trace the blue I see, to make a mark with it and better understand it, but to quantify blue, pin it next to a number, seems to drain all the richness out of this astounding color. This is the difference between a map and measurement, I suppose. Tracing versus calculating.
Maps in their most traditional uses visualize the paths of our movements, or possible lines our bodies will follow. Maps gather the ligaments of roads and trails, and always they are references for where we come into contact with the ground. Cartographers place us upon the earth, but as I note the blue around me in Alaska, my eyes always return upward. Rather than tracing where my feet land, I want to make maps of the sky, the terrain where my eyes and heart wander. Next to each of my posts, you will find a scale of the sky for each day that we are out on the trail. Each square marks an hour, so that you may see what was above me as I meandered along the Chester Creek Trail.