Disregarding the order, Hewett pulled down the parapet of the battery and with the assistance of some soldiers slewed his gun round and poured on the advancing enemy a most destructive and effectual fire.

He was Commander-in-Chief, Cape of Good Hope and West Coast of Africa, in charge of naval operations during the Third Anglo-Ashanti War, from 1873.

[3] In April 1884, Hewett led a delegation to Emperor Yohannes IV which negotiated, in exchange for free transit of guns and ammunition through Massawa, access through Ethiopian territory for the successful evacuation of the Egyptian garrisons that had been isolated in southern Sudan by the revolt of Muhammad Ahmad (also known as the Mahdi) against the Egyptian rulers.

[4] After his return from Ethiopia, Hewett was appointed Junior Naval Lord and, on 8 July 1884, was promoted to vice admiral.

From March 1886 to April 1888 he was in command of the Channel Fleet; however, his delicate health worsened and he died shortly after his retirement.