In the 1960s, Telegraph Poles Were Equipped With Nuclear Bomb Alarms

(via Atlas Obscura)  The “Bomb Alarm System,” designed and implemented by Western Union, wasn’t a secret, but it was unobtrusive enough that unless you were looking for it, you wouldn’t know it was there. Operational from 1961 to 1967, it was a part of the hidden infrastructure that was rapidly built to allow the U.S. military to respond to nuclear attacks—an extensive communications and monitoring system that presaged today’s networked world.