The Reis telephone was a rudimentary telephone invented by Johann Philipp Reis (German, 1834-1874). First built in 1860, it was based on the principle of magnetostriction. Wire coiled around iron cores and needles caused contraction when a current flowed, producing an audible click in a resonator. However, the sounds were faint, and there was little interest in the invention. The practical development of the telephone was achieved by others, such as Alexander Graham Bell.