 Complete the following phrase:  In 1825, he accompanied Frederick William Beecheys expedition to the Pacific and Bering Strait as a surveyor. In 1836 he commanded a surveying ship on the north and west coasts of Africa and in the British seas. Belcher took up the work which Beechey had left unfinished on the Pacific coast of South America. He was on board , which was ordered to return to England in 1839 via the Trans-Pacific route. Belcher made various observations at a number of islands which he visited, having been delayed by being despatched to take part in the 