On the night of August 13, 1892, Professor Barnard, while examining Venus with the great 36-inch telescope of the Lick Observatory, saw a star of the 7th magnitude in the same field with the planet. He carefully determined the exact position of this star, and found that it is not in Argelander's great catalogue, the _Durchmusterung_. Prof. Barnard finds that owing to elongation of Venus from the sun at the time of observation the star could not possibly be an intra-Mercurial planet (that is, a planet revolving round the sun inside the orbit of Mercury); but that possibly it might be a planet revolving between the orbits of Venus and Mercury. As the brightest of the minor planets--Ceres, Pallas, Juno, and Vesta--were not at the time near the position of the observed object, the observation remains unexplained. It might possibly have been a _nova_, or temporary star.[50] Scheuten is said to have seen a supposed satellite of Venus following the planet across the sun at the end of the transit of June 6, 1761.[51] Humboldt speaks of the supposed satellite of Venus as among "the astronomical myths of an uncritical age."[52] An occultation of Venus by the moon is mentioned in the Chinese Annals as having occurred on March 19, 361 A.D., and Tycho Brahé observed another on May 23, 1587.[53] A close conjunction of Venus and Regulus (α Leonis) is recorded by the Arabian astronomer, Ibn Yunis, as having occurred on September 9, 885 A.D. Calculations by Hind show that the planet and star were within 2' of arc on that night, and consequently would have appeared as a single star to the naked eye. The telescope had not then been invented.[54] Seen from Venus, the maximum apparent distance between the earth and moon would vary from about 5' to 31'.[55] It is related by Arago that Buonaparte, when going to the Luxembourg in Paris, where the Directory were giving a fête in his honour, was very much surprised to find the crowd assembled in the Rue de Touracour "pay more attention to a region of the heavens situated above the palace than to his person or the brilliant staff that accompanied him. He inquired the cause and learned that these curious persons were observing with astonishment, although it was noon, a star, which they supposed to be that of the conqueror of Italy--an allusion to which the illustrious general did not seem indifferent, when he himself, with his piercing eyes, remarked the radiant body." The "star" in question was Venus.[56] CHAPTER IV The Earth