the New Bedford ship John and Winthrop in 1887. In 1825, the trader Peter Dillon's discovery of sandalwood on the island of Erromango, highly valued as an incense in China where it could be traded for tea, resulted in rush of incomers that ended in 1830 after a clash between immigrant Polynesian workers and indigenous Ni-Vanuatu. Further sandalwood trees were found on Efate, Espiritu Santo, and Aneityum, prompting a series of boom and busts, though supplies were essentially exhausted by the mid-1860s, and the trade largely ceased. During the 1860s, planters in Australia, Fiji, New Caledonia, and the Samoan islands, in need of labourers, encouraged a long-term indentured labour trade called "blackbirding". At the height of the labour trade, more than one-half the adult male population of several of the islands worked abroad. Because of this, and the poor conditions and abuse often faced by workers, as well the introduction of common diseases to which native Ni-Vanuatu had no immunity, the population of Vanuatu declined severely, with the current population being greatly reduced compared to pre-contact times. Greater oversight of the trade saw it gradually wind down, with Australia barring any further 'blackbird' labourers in 1906, followed by Fiji and Samoa in 1910 and 1913 respectively. From 1839 onwards, missionaries, both Roman Catholic and Protestant, arrived on the islands. At first they faced hostility, most notably with the killings of John Williams and James Harris of the London Missionary Society on Erromango in 1839. Despite this they pressed on, resulting in many conversions; however, to the consternation of the European, this was often only skin-deep, with Ni-Vanuatu syncretising Christianity with traditional kastom beliefs. The Anglican Melanesian Mission also took promising young converts for further training in New Zealand and Norfolk Island. Presbyterian missionaries proved particularly successful on Aneityum, though less so on Tanna, with missionaries being repeatedly chased off the island by locals throughout the 1840s–60s. The hostile response may have been partly to blame with the waves of illnesses and deaths the missionaries inadvertently brought with them. Other European settlers also came, looking for land for cotton plantations, the first of these being Henry Ross Lewin on Tanna in 1865 (which he later abandoned). When international cotton prices collapsed after the ending of the American Civil War, they switched to coffee, cocoa, bananas, and, most successfully, coconuts. Initially British subjects from Australia made up the majority of settlers, but