Spring Oscillation

I pulled myself beneath the door sweep and exited into the outer corridor. Mounted directly to the off-white baseboard sat a flexible coiled spring doorstop with a white rubber cap. I approached the fixture. I gripped the rubber tip with both hands and bent the coil back two centimeters against its tension. Upon release, the spring snapped forward and oscillated rapidly from side to side. It generated a brief metallic hum that decayed over three seconds until motion ceased completely. The tip returned to its perpendicular rest position without deviation. The mechanical cycle remained entirely predictable.