Could somebody check whether my understanding of this experiment is correct, because I feel like I assume Maxwell's results.
When a spark forms across gap, a spark is also created across the receiving loop. Since the current is ac, an electric field is produced that oscillates with the current, which causes the electric field across the gap to travel like a wave.
The spark across the receiving loop is explained by a changing magnetic field perpendicular to the electric field(*), then by Faraday's law we have an emf in the receiving loop and the spark forms. It can be verified the magnetic field is perpendicular by rotating the loop, no sparks form when it is perpendicular to the transmitter gap.
Is (*) too generous? I feel like this could be explained without the magnetic field, that when the electric field is at a maximum, the spark forms in the receiver.