The third and youngest son of Sir Arthur Howlett, KCB, and Mary Presgrave, his wife, was born in India on 29 September 1856. He was educated at Cranbrook School and Eastbourne College, before entering the Medical School at King's College, London. He served as house surgeon at King's College Hospital in 1877, and was appointed demonstrator of anatomy at the London Hospital in 1879. From 1 October 1880 until 30 September 1882 he was resident surgical officer at the Manchester Royal Infirmary, after which he went for a few months to the Monsall Fever Hospital. He settled in Hull in 1883 and was elected assistant surgeon to the Hull Royal Infirmary in the vacancy caused by the death of Dr Kelburne King, but did not become surgeon until 1897; he was appointed consulting surgeon on his retirement in 1914. He always took an active interest in the affairs of the Infirmary, was for twenty-two years a member of the board of management, and was chairman of the standing medical committee. He was also medical officer at Hull to the General Post Office and to HM Prison, making himself so respected in the latter position that on his death the warders asked to be allowed to act bearers of the coffin. Howlett busied himself, from their first introduction, with X-rays, both experimentally and clinically. He was appointed the first radiologist to the Hull Infirmary and held office until 1922. He married on 3 January 1884 Amy Davinia, only daughter of the Rev Richard Masters Hutchins, MA, of Trinity College, Cambridge, who survived him with two sons: Lieutenant-Colonel E G Howlett, MC, of the 7th Rajput Regiment, and Arthur Stanley Howlett. He died on 8 September 1930. Howlett was at one time an enthusiastic football player; in later life he turned to painting and produced some good work in portraiture and seascape.