In 1770, Thomas Forrest (c.1729–c.1802) was involved in establishing a new free port at Balambangan, Malaysia, which would improve the British East India Company's trade routes eastwards. In 1774 he agreed to lead an expedition on the Company's behalf to find out more about the waters between Malaysia and New Guinea. This 1779 publication (reissued in the Dublin edition) tells the story of Forrest's fifteen-month voyage in a small local vessel crewed by Malaysians, exploring the archipelago between the Philippines and present-day Indonesia. A French translation appeared in 1780, and linguist Wilhelm von Humboldt referred to the book fifty years later. Forrest describes the islands, their populations, and their vegetation, including different spices. He discusses relations between local rulers, and the rivalries between the British and the Dutch, particularly as regards control of the spice trade. The book also contains a substantial vocabulary of the Maguindanao language.