collected these materials over the period 1963–1975 and also commenced restoration work on the diverse range of rock carvings and headstones from the major burial grounds. The items collected by Lavaring were preserved, and many have since found their way into state and federal collections, including the National Museum in Canberra, where a muzzle-loading rifle and a set of manacles are preserved (the latter being used to ensure that no one left the station without medical clearance). One of the most historic features of the quarantine station is the series of engravings along the escarpment adjacent to the jetty. The carvings were executed by people staying at the quarantine station, and cover an extensive period that stretched from the early nineteenth century to the mid-twentieth century. Some were executed by stonemasons and sculptors and show a high degree of skill. More carvings are located at the rock formation known as Old Man's Hat. History The Quarantine Station was established primarily to regulate the risk of disease importation through the migration of free and convict Europeans, and the arrival of merchant shipping. There was always a close link between the requirement for quarantine and the ebb and flow of sea-borne immigration; and the growth of the Quarantine Station from the 1830s parallels the changes in immigration policy and practice. The other major influence was the imperative to limit disruption to the increasingly commercially-sensitive shipping industry. As the dominant headland of the harbour, North Head was of importance in navigation from the time of the First Fleet. By 1809 navigational plans were showing an obelisk, located in what was to become the Quarantine Station precinct, presumed to have been used as a channel marker for vessels negotiating the Sow and Pigs Reef. A obelisk still exists on this site, which may be the original marker, making it potentially one of the oldest European structures on Sydney Harbour. Up until the 1830s, the majority of ships requiring quarantine were convict transports, and being under government contract, the somewhat informal proclamation of quarantine by the Governor of the day was easy to enforce. One reason for the introduction of formal statutory regulation for quarantine in NSW in 1832 was the increasing rate of free immigrant vessels entering port. In 1831 thirty four immigrant ships had arrived, and this increased to 63 in 1832. The captains of these free vessels were less ready to comply