The oldest known pencil in the world, found in a timbered house built in 1630. Getty Images.

“Ink is the cosmetic that ideas will wear when they go out in public. Graphite is their dirty truth.” (Henry Petroski, pencil historian)

(Tim Harford, “Have we all underrated the humble pencil?” http://www.bbc.co.uk, 6-26-19)

(c) 2019 JMN