4347 entries. 93 themes. Last updated April 18, 2014.

Invention of Modern Pencil Lead (1795)

During the Napoleonic wars, France, under naval blockade imposed by Great Britain, was unable to import pure graphite sticks from England. Nor could France import English pencils or the inferior German pencils. To solve this problem, in 1795 Nicholas Jacques Conté, an officer in Napoleon's army, discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied.

"This method of [pencil lead] manufacture which had been earlier discovered by the Austrian Joseph Hardtmuth of Koh-I-Noor in 1790 remains in use."