From verso of card: "All the elements of air defence are represented in the control room, including the commanders . . . of the anti-aircraft artillery, the searchlights, the balloon barrage, and the fighter squadrons. They sit in a gallery overlooking the large map table. The men round the map table receive reports of enemy raids by telephone from the Observer Corps centres, who in their turn receive reports from the posts dotted about the country. The raids are plotted on the map table so that the commanders can see at a glance the numbers of the enemy, and by what routes they are coming in. On this information orders are sent out to the Fighter Squadrons telling them where to go to intercept the enemy."