Carrington Event

…Some telegraph stations that used chemicals to mark sheets reported that powerful surges caused telegraph paper to combust.… When American Telegraph Company employees arrived at their Boston office at 8 a.m., they discovered it was impossible to transmit or receive dispatches. The atmosphere was so charged, however, that operators made an incredible discovery: They could unplug their batteries and still transmit messages to Portland, Maine, at 30- to 90-second intervals using only the auroral current. Messages still couldn’t be sent as seamlessly as under normal conditions, but it was a useful workaround. …