page_title: Hornsby Water Clock
section_title: Swiss pendulum clock
hierarchical_section_title: Hornsby Water Clock / Individual clocks / Swiss pendulum clock
caption_attribution_description: English: Hornsby Water Clock: detail of clockface on the Swiss pendulum clock.
context_page_description: The Hornsby Water Clock, titled Man, Time and the Environment is a piece of kinetic sculpture, a decorative fountain and a functional clock in the Florence Street pedestrian mall in Hornsby, New South Wales, Australia. Unveiled in 1993, the sculpture was designed and engineered by Victor Cusack and constructed of bronze, stainless steel and glass by Victor and his foundry floor manager Rex Feakes. Construction, including alterations to the mall, cost over A$1 million and took two and half years; thereafter, chicken bones and other carelessly discarded items caused many breakdowns before the water filtration system was upgraded.
context_section_description: It is claimed that this is "undoubtedly the largest water-driven pendulum clock ever built" and has the same 4 second pendulum cycle time as the Great Clock of Westminster (often erroneously known as "Big Ben"), though the pendulum weight is heavier at 350 kg (770 lb). The design is based on one drawn up by Claude Perrault in 1669 but never built.
  The 5 m (16 ft) pendulum mounted on a knife-edge to minimize friction and is kept moving by the "top drive" (the top moving glass chutes); as one side becomes full, it tilts the mechanism over to its side so that the water is discharged and the other tank receives the water supply underneath the sea eagle sculpture.
  Seconds are marked by the rotation of the glass wheel which has 30 pins around the edge. Each half-cycle of the pendulum (2 seconds) results in the wheel moving to the next pin so it completes a cycle every minute. A cam on the "second wheel" releases the holdback arm on the lower drive every 30 seconds, discharging 100 litres (26 US gal) of water and moves the minute hand once a minute and the hour hand once every 12 minutes.
  Instead of numbers, the hours on the clock face are marked by the letters that make up "Dare we forget". The clock is decorated with various animals to "remind us that we are losing species on our earth due to our sometimes insensitive land use" and aboriginal art forms "as a reminder that Hornsby once maintained a strong tribal population that suffered the same fate as many animals are suffering".
  The pendulum clock is used to control the rotation of the pontoon, the chimes and to supply water to the Chinese clock.
caption: Swiss pendulum clock section of the fountain
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