Multiple microphone for voice modulation of Poulsen transmitters

In 1910, the German Navy began equipping their ships with telephony accessories for the telegraphy arc converters that had been installed the year before. As amplifiers were not yet available, the microphone needed to be connected directly to the antenna circuit, which was also supplied with several kilowatts of power. However, the carbon microphones used at the time were not suited to such high amounts of power, meaning several microphones had to be connected next to each other.