Minute from WSC to Home Secretary [and Minister of Home Security, Herbert Morrison] suggesting the use of air raid sirens "requires immediate consideration" because of the creation of a "great deal of needless unrest", commenting on the need to clarify the purpose of the siren, what he has noticed of people's reactions, and arguing for more use to be made of shelters. [Carbon; annotated by Sir Desmond Morton, Prime Minister's Personal Assistant].