= Telephone
{title2=1870s}
{wiki}
We are at a point in history where the <electrical telegraph> is well established.
But people don't want to press letters one by one on a switch. They want to talk!
The first phones appear to have used telegraph lines directly.
Also wired phones don't require <modulation>, which likely made their development much easier than wireless voice transmission. You just send the signal as a voltage differential directly obtained from the air pressure: <how the telephone works>.