Harry was educated at Pembroke College, Cambridge and at St Thomasís Hospital, London - entering in 1903, he qualified B.A. in Natural Sciences; M.A.; and M.R.C.S., L.R.C.P. in 1909. He died whilst in service at the Military Hospital, Lichfield. He was the son of Henry Sinclair and Anne Leigh Keturah Hall of 9 The Avenue, Clifton, Bristol.