We purchased a new home and it has an in-ground pool (spec's below in my sig line). One of the water features it has is built into the side of the pool, above the waterline. When I turn the valve on, water gushes out of it, similar to a garden hose. It's flush with the wall, but the hole is threaded, as if it had some attachment on it. When I was a kid, we had a pool and I remember there being some sort of small white adapter that produced a canopy of water - like a rainbow across the pool. My guess is that is what was here at one time, but they either removed it, or it broke and they didn't replace it.
Hopefully I'm making sense. Anyone know where I can find such a thing?