October 11, the dark stripe in the tail had almost vanished, the secondary tail was no longer to be seen, and the main tail was curved like an ostrich plume. Its length was now judged to be about 30°, and the nucleus had somewhat diminished in brightness. By October 15 the comet was considerably fainter and smaller, as seen with the naked eye, and it was bent southward like a sail wafted by a celestial breeze. After the middle of October, the comet was best seen from the southern hemisphere, and the last glimpse obtained in the northern hemisphere was on October 25, when it was at an altitude of 3°, the sky fortunately being very clear. The nucleus was still bright, but the tail was only 1° long. Its course was then followed by Maclear, Royal Astronomer at the Cape of Good Hope, who reported that on December 23 the comet was merely a faint nebulous body, about 90″ in diameter, with a slight central condensation of light and no trace of a tail. Thus, it vanished in the remote depths of space, in the same undecorated condition as when it first made its eventful début to gladden the eyes of mortals on planet earth. Its visit lasted but one hundred and seventy-seven days, from the time of its first appearance until it took its departure along a track which will not bring it within our ken again until nearly two thousand years have rolled away. BIOGRAPHICAL NOTE.—G. B. Donati, the Italian astronomer, was born at Pisa, in 1826. At the age of twenty-six, he obtained a post in the observatory at Florence, and there by his superior abilities, acquirements, and unwearied application to duty soon gained a high reputation among the men of science of his native country. He became known to the world in 1858, by his discovery of the magnificent comet called by his name. In 1864 he was appointed director of the observatory in which he had worked so efficiently for twelve years. He then undertook the arduous task of superintending the erection of a new and more convenient observatory on the site of Arcetri, near Florence. All difficulties were conquered, the new observatory was in working condition, and the director had entered upon a new series of observations when his labors were suddenly cut short by death. He died at his home in Arcetri, September 29, 1873. CHAPTER FOUR COMETS IN DISTRESS “Thou comest whence no mortal seer can know, Thou goest whither nothing human dreams.” —ANON.