from the year 1000 to the year 1800, in which both sun-spots visible
to the naked eye and great displays of the auroral lights were
recorded, first set Rudolf Wolf on the track of this discovery. The
first notable proof of the suspected connection was furnished with
dramatic emphasis by an occurrence which happened on September 1,
1859. Near noon on that day two intensely brilliant points suddenly
broke out in a group of sun-spots which were under observation by Mr
R. C. Carrington at his observatory at Redhill, England. The points
remained visible for not more than five minutes, during which interval
they moved thirty-five thousand miles across the solar disk. Mr R.
Hodgson happened to see the same phenomenon at his observatory at
Highgate, and thus all possibility of deception was removed. But
neither of the startled observers could have anticipated what was to
follow, and, indeed, it was an occurrence which has never been
precisely duplicated. I quote the eloquent account given by Miss
Clerke in her History of Astronomy During the Nineteenth Century.

This unique phenomenon seemed as if specially designed to
accentuate the inference of a sympathetic relation between the
earth and the sun. From August 28 to September 4, 1859, a magnetic
storm of unparalleled intensity, extent, and duration was in
progress over the entire globe. Telegraphic communication was
everywhere interrupted -- except, indeed, that it was in some cases
found practicable to work the lines without batteries by the agency
of the earth-currents alone; sparks issued from the wires; gorgeous
auroras draped the skies in solemn crimson over both hemispheres,
and even in the tropics; the magnetic needle lost all trace of
continuity in its movements and darted to and fro as if stricken
with inexplicable panic. The coincidence was even closer. At the
very instant of the solar outburst witnessed by Carrington and