"[...]an incandescent lamp attached to nothing but a coil wound antenna, which was lit up by a transmitter [...]"
A neon bulb held near an HF transmitter will also light without contact. In amateur radio circles it was reckoned that a nice red glow was a good sign. If there were purple tinges then there were possibly parasitic oscillations that needed to be cured.
Biting the hand that feeds IT
