The Sun sometimes experiences violent expansions, perturbations, tempests, and magnetic storms. The smallest disturbances which happen in our formidable star are transmitted to us. For instance: the years 1904 to 1908 were very strange so far as the Sun was concerned. Instead of the single maximum which is usually observed, there were two maxima, one in 1905 and another in 1907, 1906 being less active. The curve traced to represent the number of sunspots shows two peaks, in 1905 and 1907 respectively, with a depression in 1906. It is the same with terrestrial magnetism: maxima in 1905 and 1907, with a slight weakening in 1906. When I discovered this unexpected coincidence for 1906, several sceptics were greatly surprised. Yet it is true. It was the same when I accused the Sun of being the author of the interruption of telephonic and telegraphic communication on September 25, 1909, which took place over the whole of France, in all Europe, and throughout the world. The telephone girls were unjustly blamed and the telegraph engineers were equally innocent. Why had no newspaper thought of it? Perhaps because politics are cultivated more than science in the papers of our unbalanced days. I do not accuse our country more than another, the English, German, American, Australian, and other editors having been equally astray concerning the cause of the perturbation. On that day the intensity of the earth-currents which produced the breakdown was 50 million amperes, whereas the instruments work regularly with 10 to 12 milliamperes. The whole terrestrial globe had been plunged into a magnetic field of great intensity, into a veritable dynamic ocean originating in a solar torrent. A large group of sunspots surrounded by faculæ had arrived on the eastern limb of the solar globe on September 17, and had gradually advanced towards the central meridian of the solar hemisphere turned towards us by the Sun’s rotation. On the 19th, this group had become much larger. The spectroscope had indicated violent eruptions. The enormous group of sunspots was visible to the naked eye and numerous photographs of it had been taken at the Juvisy Observatory. It passed the central meridian of the Sun on the morning of September 24 and continued its course towards the western limb, disappearing from sight on October 1. The magnetic perturbation which struck our planet arrived 30 hours after the passage of this group of sunspots across the central meridian of the solar hemisphere facing us. We had already, on October 31, 1903, observed a similar cosmic phenomenon, and previously on November 18, 1882, and August 3, 1872. Even before that date a similar event took place on September 1, 1859. But memory is short, and in any case astronomical ignorance is universal.