With the gradual increase in the popularity of the telephone, and early experiments in radio, by the beginning of the 20th century the mass production of microphones was well underway. These were almost exclusively of the simple carbon variety found in telephones right up to the 1980s. There was even an appetite amongst hobbyists and enthusiasts for making your own!
This charming little book (circa 1910) contains all sorts of useful information and suggestions; including a method, ( based on an 1878 experiment by Professor Hughes), for making a microphone out of 3 NAILS, a battery and some wire!! ……….. So much cheaper than a Neumann U87 !!!
As sound hits the middle nail it vibrates, causing tiny fluctuations in the current on its way to the receiver………
Let me know if you get this to work!!!! Maybe give me a ring!