In January, police used clubs on 400 anti-war/anti-Vietnam protesters outside of a dinner for U.S. Secretary of State Rusk. In February, students from Harvard, Radcliffe, and Boston University held a four-day hunger strike to protest the Vietnam war. Ten thousand West Berlin students held a sit-in against American involvement in Vietnam. People in Canada protested the Vietnam War by mailing 5,000 copies of the paperback, "Manual for Draft Age Immigrants to Canada" to the United States. On March 6, five hundred New York University (NYU) students demonstrated against Dow Chemical because the company was the principal manufacturer of napalm, used by the U.S. military in Vietnam. On March 17, an anti-war demonstration in Grosvenor Square, London, ended with 86 people injured and 200 demonstrators arrested. Japanese students protested the presence of the American military in Japan because of the Vietnam War. In March, British students (opposing the Vietnam War), physically attacked the British Defense Secretary, the Secretary of State for Education and the Home Secretary. In August, the 1968 Democratic National Convention in Chicago was disrupted by five days of street demonstrations by thousands of protesters. Chicago's mayor, Richard J. Daley, escalated the riots with excessive police presence and by ordering up the National Guard and the army to suppress the protests. In September, the women's liberation movement gained international recognition when it demonstrated at the annual Miss America beauty pageant. The week-long protest and its disruption of the pageant gave the issue of equal rights for women significant attention and signaled the beginning of the end of "beauty pageants" as any sort of aspiration for young females.