In the early to mid 20th century the principal source of income for Gilbert islanders was from working on the production of phosphate from the deposits on Banaba (Ocean Island), an island to the west of the Gilbert Islands. In addition, coconut palms were cultivated on some of the islands. All labor was supervised by the British and every effort was made to see that the wages and living conditions were fair and adequate. Sanitary inspections by the British did much to improve the general living conditions on most of the islands.