Lars Ericsson studied at the village school for 5 years. This experience taught him to read and write, and was his only formal education. Nevertheless, he constructed Sweden's first telephone line at the age of 17. The idea behind the telephone was simple: a person speak into a membrane, which starts to vibrate and causes a pin to vibrate. These vibrations are then sent to the other telephone, via a power cable, where another pin and membrane begin vibrating and the receiver hears what is being said. German scientist, Johann Philipp Reis, had built such a telephone in1861.