The aurora which occurred as a result of the "great geomagnetic storm" on both 28 August and 2 September 1859, are thought to be perhaps the most spectacular ever witnessed throughout recent recorded history. The latter, which occurred on September 2 as a result of the exceptionally intense Carrington-Hodgson white light solar flare on September 1, produced aurora so widespread and extraordinarily brilliant that they were seen and reported in published scientific measurements, ship's logs and newspapers throughout the United States, Europe, Japan and Australia. It was said in the New York Times that "ordinary print could be read by the light [of the aurora]".
The aurora is thought to have been produced by one of the most intense coronal mass ejections in history, very near the maximum intensity that the sun is thought to be capable of producing. It is also notable for the fact that it is the first time where the phenomena of auroral activity and electricity were unambiguously linked. This insight was made possible not only due to scientific magnetometer measurements of the era but also as a result of a significant portion of the 125,000 miles of telegraph lines then in service being significantly disrupted for many hours throughout the storm.
Some telegraph lines however, seem to have been of the appropriate length and orientation which allowed a current (geomagnetically induced current) to be induced in them (due to Earth's severely fluctuating magnetosphere) and actually used for communication. The following conversation was had between two operators of the American Telegraph Line between Boston and Portland on the night of the 2nd and reported in the Boston Traveller.
The conversation was carried on for around two hours using no battery power at all and working solely with the current induced by the aurora, and it was said that this was the first time on record that more than a word or two was transmitted in such manner.
