A cleaner sweeping the archers between Downing Street and the foreign office quadrangle today, discovered a home-made bomb behind one of several packing cases stacked against the foreign office wall. The bomb consisted of 2 electric batteries bound together with wire and wired to a small glass jamjar, with the metal cover, in which was the charge. The Home Office laboratory examination showed that if the bomb had been detonated it would have caused "very considerable damage". 19 August 1947