Waterphone Instrument
The Waterphone
The Waterphone is an extraordinary musical instrument that offers a unique playing experience, allowing for both bowing and percussive techniques with a mallet. Crafted from stainless steel with brass rods, its distinctive sound is influenced by the water contained within, which ripples and moves to affect the sound production. The resonance intricacies within waterphones are remarkably complex, making playing it a blend of simplicity in expression yet complexity in operation. Often likened to a vibration machine, the Waterphone’s sound lingers and reverberates within its coherent system of metal, air, and water, creating a mesmerizing auditory experience. Richard Waters. is credited as the inventor of this remarkable musical device, and I hold immense respect for his beautiful craftsmanship and innovation.
There is a historical background of waterphone instruments on Wikipedia.

Playing technique
You can play the waterphone by using the bow or treat it like a percussion instrument using a soft mallet. You can softly strike the metal rods or the bottom plate. In my opinion the greatest potential of my precisely tuned waterphones is released by using the bow.
You can use any bow. For the violin, cello or double bass. All theese work and it’s up to you and you preferences. I use the cello bow and double bass rosin for the winter time (it is more sticky).
Every rod has several harmonic frequencies that it can produce. In the lower part of the rod there is the higher sound, slightly below the middle of the rod there is the middle sound and in the upper part there is bass sound (On longer rods, this bass note becomes so low that it is no longer audible). When we consider the longer rod there is more playable sounds, up to five. Beyond the bow placement on the rod there are other factors such as total energy and speed of 1the bow / bow pressure ratio. Theese also decide about the resulting sound. When you learn how to put a lot of energy into the resonant rod, the magic will happen. There is a small amount of water in the waterphone, typically ranging from 20 to 200 ml, depending on the desired sound effect. By tilting or moving the instrument, you can manipulate the water inside to affect the sound and “bend” the pitch. The specified amount of water is for achieving a more classical waterphone sound, but you can add as much water as you want and even partially submerge the entire waterphone in water for a variety of sonic textures. Additionally, there is plenty of potential in playing the “dry” waterphone, where the bottom plate resonates completely loose, offering alternative resonance characteristics.