Chapman was born in London. He studied at the East India Company’s Military Seminary at Addiscombe, where he won several exam prizes. After a year at Chatham he joined the Bombay Engineers. As Second Assistant in the Department of Roads and tanks he took charge of the works on the Agra road from the foot of the Thull Ghaut to Candore from 1846, receiving much praise for his work. He married Brigadier Twemlow’s second daughter Charlotte in Aurungabad in June 1848.

After a leave of absence spent researching engineering projects in England in 1851, he joined the Institution of Civil Engineers as an Associate Member. On his return to India in October 1852, he was appointed to the survey of the construction of a canal between the Indus and Kurrachee. He concluded that a railway line would offer greater advantages. While investigating this he had a fatal accident on the river Indus in December 853. After his untimely death the road he had worked on was renamed Chapman Road, Thull Ghaut.

Brigadier Twemlow (1796 - 1877) of the Royal (Bengal) Artillery was the commandant at Aurungabad (Nizam’s Contingent) who had a distinguished military career in India from 1812. He lived in a bungalow at Roza, ‘an old Mohammedan tomb surrounded by a walled garden’, (Francis Egerton, ‘Journal of a Winter’s tour in India’, 1852, vol. II, p. 225).

He returned to England in 1853 and devoted himself to scientific and archaeological pursuits.