Attendance figures at large assemblies can be recorded scientifically, using technology from the city's universities, according to a pilot study. At Thursday's candle-light vigil, equipment was put at the Victoria Park entrance near the Central Library to count people entering by detecting their body heat. The effort was a joint project of Chinese University's school of journalism and the University of Hong Kong's public opinion programme. Clement So York- kee of Chinese University said the equipment was being tested and the research team was still calculating the number. He estimated the number in the park at 108,000. The size of the crowd outside the park could not be counted. The figure fell between the 150,000 announced by the organiser, the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, and the 62,800 given by the police. Professor So said the research team might use the equipment again in the annual march for democracy on July 1. Legislative Council president Tsang Yok-sing said he believed Beijing understood residents' views on the crackdown. 'I think [the high turnout] was natural because it was the 20th anniversary. The demands by people who attend the vigil every year are consistent ... The central government is very clear about their demands.'