Apparently these cord things go from a radio trigger to a flash gun. I am amazed, because I normally use lycopodium power spread out in a tray and ignited with a flintlock mechanism to provide the studio flashes. The idea of hooking up one of Mr. Marconi's wireless sets to this seems revolutionary.
Quite how the Packard shutter on the studio Calotype camera operates the transmitting key of the Marconi machine is still unclear. I daresay the young man will explain it when he comes in later in the day.
I hope he remembers to shout into my ear trumpet...