Crowther was selected to accompany the missionary James Frederick Schön on the Niger expedition of 1841.

He works closely with his laboratory's illustrator, Carol Abraczinskas, and shot his own video of the Niger expedition.

He next obtained an appointment as master-at-arms in the Albert, which with the Wilberforce and the Soudan sailed on the Niger expedition of 1841.

After a trip to West Africa in 1851, he was chief surgeon on the Niger expedition (1854-55).

He took part in the Niger expedition of 1841.

The steam vessels built for the Niger expedition of 1841 were fitted with ventilation systems based on Reid's Westminster model.

He was present during the engagement with the Peruvian rebel ship Huáscar in 1877 and also took part in the Niger expedition in 1882.

He participated in the Niger expedition of 1841 as the African Civilization Society's scientist, with Allen and Thomson.

The government in turn backed the Niger expedition of 1841 (not including Buxton) put together by missionary organizations.

At the end of 1840 he travelled to England to meet the African Civilization Society, then planning the Niger expedition of 1841.