Police route Communists with tear gas at demonstration during congress opening. In this photograph, taken from the steps of the Capitol, shows Communists milling about in a cloud of tear gas, which police used to break up a demonstration during the opening of the 71st Congress. Some 300 communists took part in the demonstration and police who attempted to tear up the their banners and drive the crowd away made slow progress with their night, until the tear gas was brought into action. January 1930