From Henry Petroski's book, The Pencil (1989)
Henry David Thoreau seemed to think of everything when he made a list of essential supplies for a twelve-day excursion into the Maine woods. He included pins, needles, and thread among the items to be carried in an India-rubber knapsack, and he even gave the dimensions of an ample tent…. He wanted to be doubly sure to be able to start a fire and to wash up, and so he listed: “matches (some also in a small vial in the waist-coat pocket); soap, two pieces.” He specified the number of old newspapers (three or four, presumably to be used for cleaning chores), ….… he advised like-minded observers to carry a small spyglass … a pocket microscope … tape measure … and paper and stamps, to mail letters back to civilization.
But there is one object that Thoreau neglected to mention, one that he most certainly carried himself. For without this object Thoreau could not have sketched … fauna…. Without it he could not label his blotting paper … or his insect boxes … record measurements … write home … make his list. Without a pencil Thoreau would have been lost in the Maine woods.According to his friend Ralph Waldo Emerson, Thoreau seems always to have carried, “in his pocket, his diary and pencil.” So why did Thoreau … neglect to list even one among the essential things to take on an excursion? Perhaps the very object with which he may have been drafting this list was too close to him, too familiar a part of his own everyday outfit, too integral a part of his livelihood, too common a thing for him to think to mention.
Image from HERE.