Pellion was a topographical painter, naval draughtsman and midshipman aboard l’Uranie under the command of Louis de Freycinet during the voyages of 1817-1820. Pellion made many sketches in NSW, including views of Cox’s Pass and Cox’s River and portraits of the local aborigines. In 1819, Governor of New South Wales, Lachlan Macquarie, invited the French explorer to cross the Blue Mountains on a new road, with Pellion accompanying him.