University of Bristol - Historical Photographs of China reference number: JC-s006. Post card (undivided back). This water clock was first made in about AD 1324, and was destroyed and restored many times. It was housed in the Double Gateway in the old city, Canton (Guangzhou). Water dripped from one copper bucket to another, over a twelve hour period. A float on the lowest bucket indicated the approximate time of day and this time was exhibited on a board outside the building. On another post card, this clock was described as the 'The Water Clock of the King Pak Tower, Canton'. The image reproduced in colour on the post card is a photograph by A Chan (Ya Chen). See JC-s020.