Mihajlo Pupin, a physicist born in Idvor (Serbia, then Austro-Hungarian Empire), patents in 1894 the loading coil (Pupin coil): an inductor inserted at regular intervals in telephone cables that reduces signal attenuation and multiplies the range of cable communications. AT&T bought the patent for $185,000 in 1901 — one of the highest sums paid up to then for a patent — and installed Pupin coils throughout the North American telephone network. Modern long-distance telephony is a direct consequence of his invention. Pupin wrote his autobiography From Immigrant to Inventor (1923), which won the Pulitzer Prize, becoming one of the few inventors to document his own erasure.