In 1844 he travelled to the United Kingdom to studied botany at the Royal Botanic Gardens, Kew. On the recommendation of Sir WJ Hooker, he was appointed naturalist on the voyage of exploration of the American west coast and Pacific by Henry Kellett on HMS Herald, 1847-1851, along with the naturalists Thomas Edmondston, and John Goodridge. The expedition returned via Hawaii, Hong Kong and the East Indies, calling at the Cape in March 1851. Here he met up with his old acquaintance Zeyher, and with Baur and Juritz they climbed Table Mountain on 13 March 1851, Ecklon being unwell and unable to accompany them. On 16 March Zeyher introduced him to Bowie at Wynberg. He left the Cape on 27 March and was back in England on 6 June 1851. The botanical results of the voyage were published as Botany of the Voyage of HMS Herald and he was awarded a Ph.D. by the University of Göttingen in 1853.