Show london will use rattles in warning of gas raids LONDON sirens and hand rattles will be used to give warning of air raids in great br britain i t a in boef rey lloyd parliamentary under secretary for home affairs disclosed in an address to the ladies carlton club of london the signal for an air raid action warning will be an intermittent siren blast or a continuous blast alternately rising and falling in pitch he said the raiders past signal will be a continuous blast for two minutes of the siren keeping at a steady pitch gas warnings which are much more local in character will be given by hand rattles sounded by air raid wardens |