brass pins above each finger hole) 45-jet chromatic / concert Whereas park and pool hydraulophones are usually 12-jet diatonic, concert-hydraulophones are usually 45-jet chromatic. 45-jet hydraulophones have a 3 octave range of A to E, chromatic, plus an additional A-flat below the lowest A. The playing compass (45 water jets) is the same as the sounding range (45 notes). 12-jet hydraulophones are installed in public spaces, but there is a 45-jet south hydraulophone at the Ontario Science Centre, a concert-hydraulophone having this precise range and compass. Themed As public art installations, hydraulophones can be made in various themes and designs. An example of a theme-specific hydraulophone is the Aquatune located at the main entrance to the Legoland waterpark in Carlsbad California. This hydraulophone, which Legoland describes as "a musical water stand", is the centerpiece of the entranceway, and is flanked on either side by educational installation exhibits, such as water tables where participants can build water dams from lego blocks, and learn about laminar and turbulent flows through various flow channels. Cold weather Hydraulophones may be built into hot tubs for use in cold weather. This solves the problem of keeping the hydraulist warm, as well as keeping the hydraulic fluid (e.g. water) heated by way of standard pumping and heating equipment. In this kind of hydraulophone (e.g. balnaphone, from the Greek "balnea" meaning "bath") the hydraulist is immersed in the hydraulic fluid used by the instrument. Percussion hydraulophone Most hydraulophones sound continuously for as long as a finger hole is blocked. However, the WaterHammer hydraulophone produces sound from impact (water hammer) that dies down after being initially struck, thus sounding more like a piano than the more typical "underwater pipe organ" hydraulophone. The WaterHammer Hydraulophone uses the water hammer principle for hard-hitting percussive musical notes. World's largest Presently the world's largest hydraulophone is located in the outdoor plaza of the Ontario Science Centre, one of Canada's landmark architecture sites. It is also Toronto's only freely accessible aquatic play facility that runs 24 hours a day. This hydraulophone is not put on display during winter months. Installations Examples of hydraulophones that have been installed around the world: Chicago Children's Museum (Chicago, USA) Thinkery Children's Museum (Texas, USA) Legoland California (Carlsbad, USA) Experimentarium (Copenhagen, Denmark) Sydney Olympic Park Aquatic Centre (Sydney, Australia) Baylor University (Waco, USA) Ontario Science Centre (Toronto, Ontario, Canada) African Lion Safari (Toronto, Ontario, Canada) University of Toronto