The man in the picture on Wikipedia is holding a waterphone in his left hand.
A waterphone is a bowl, with a hollow cylinder, partly full of water, stood up in the middle. Several brass rods connect the top of the cylinder to the edge of the bowl.
Then a bow of the sort that would normally be used for a stringed instrument, like a double bass, is pulled across one of the brass rods.
When the bow is pulled across the glass rod, the waterphone makes a sound.
This sound is vibrant and ethereal. In other words, it sounds quite thin, probably quite piercing, and maybe a bit crackly. I don't really know; I've never heard one.
EDIT: On the other hand, the YouTube clips are probably a better guide than that.
A waterphone is a bowl, with a hollow cylinder, partly full of water, stood up in the middle. Several brass rods connect the top of the cylinder to the edge of the bowl.
Then a bow of the sort that would normally be used for a stringed instrument, like a double bass, is pulled across one of the brass rods.
When the bow is pulled across the glass rod, the waterphone makes a sound.
This sound is vibrant and ethereal. In other words, it sounds quite thin, probably quite piercing, and maybe a bit crackly. I don't really know; I've never heard one.
EDIT: On the other hand, the YouTube clips are probably a better guide than that.