Delevingne became an expert on factories, and contributed a lengthy article to "The Times" in July 1933, to coincide with the centenary of the establishment of the Factory Inspectorate. In his 1950 obituary, "The Times" wrote that Delevigne was "undoubtedly an unobtrusive, but powerful, force behind much of the factory legislation that was passed during the first quarter of the present century. This was a subject that he knew from end to end, not only on its practical but also on its historical side."