 The cross represents the coat of arms of the House of Savoy, rulers of Piedmont-Sardinia.The history of marking the Western Australian border on the ground states that the "Austral Pillar" and the "Deakin Pillar" are points used to determine their position east of Greenwich and then fix a border from, in this case used to determine the line of the 129th meridian east longitude, as the Western Australian border.The Deakin Obelisk and the Kimberley Obelisk in Australia are used in a slightly different way, in that a line is run north and south through a point on the obelisks, formed by a copper plug embedded into the top centre of the concrete obelisks.