Petherick with his wife, Katherine
In 1845 John Petherick entered the service of Mehemet Ali, and was employed in examining Upper Egypt, Nubia, the Red Sea coast and Kordofan in an unsuccessful search for coal.
In 1848 Petherick left the Egyptian service and established himself as a trader, dealing largely in gum arabic. He was at the same time made British consular agent for the Sudan. In 1853 he moved to Khartoum and became an ivory trader.
Petherick returned to England in 1859 where he made the acquaintance of John Hanning Speke, who was at the time arranging for his (Speke's) expedition to discover the source of the Nile. While in England Petherick married Katherine Harriet Edlman, and published an account of his travels.
Petherick's first work and its title-page
Petherick returned to the Sudan in 1861, accompanied by his wife, and with the rank of consul. He was entrusted with a mission by the Royal Geographical Society to convey to Gondokoro relief stores for Captains Speke and Grant. Petherick got boats to Gondokoro in 1862, but Speke and Grant had not arrived. Having arranged for a native force to proceed south to get in touch with Speke and Grant, Mr and Mrs Petherick and his wife undertook another journey, making important collections of plants and fishes. They arrived back at Gondokoro (where one of their boats with stores was already stationed) in February 1863, four days after the arrival of Speke and Grant, who had meantime accepted the hospitality of Samuel Baker. Speke later publicly accused Petherick of failing to fulfill his commitment.