The telephone used was Edison's chalk cylinder or electromotograph type of telephone.
It has sometimes been claimed that Edison's proposed elevated plates anticipated the subsequent invention by Marconi of the aerial wire or antenna, but it is particularly to be noticed that Edison employed no spark gap or means for creating electrical high frequency oscillations in these wires.
There is no evidence that this plan of Edison's was practically operative as a system of telegraphy.
- Edison's Microphone Transmitter.
A cylinder of chalk was used in some of Edison's later experiments with this receiver.
In these experiments the electric current passed through the fingers of the operator's hand, which thus took the place of the spring in Edison's apparatus.
Edison's telephone patent was granted for the United Kingdom.