A barograph is a recording aneroid barometer. A barograph is used to measure pressure. The pointer in an aneroid barometer is replaced with a pen. It produces paper or foil chart called a barogram that records the barometric pressure over time.Barographs use one or more aneroid cells acting through a gear or lever train to drive a recording arm that has at its extreme end either a scribe or a pen. A scribe records on smoked foil while a pen records on paper using ink, held in a knib.