1811 I., Sept.-Oct.—A very fine comet. The tail was branched; it did not, however, exceed 25° in length and about 6° in breadth. Sir W. Herschel found the nucleus to be 428 miles in diameter. This remarkable comet remained visible during a period extending over seventeen months. Its period is approximately 3000 years. 1843, Mar.—Visible in the daytime. On Mar. 4 its tail was 69° in length; it was very narrow, being only 1-1/4° in breadth throughout. At perihelion this object passed very near to the Sun, like the great comet of 1680. it revolves in an elliptical orbit; period about 376 years. This comet swept past perihelion with a velocity of 366 miles per second! The real length of its tail was 200 millions of miles! 1858 VI., Sept.-Oct.—Donati’s Comet: one of the most brilliant comets of the 19th century. Early in October it displayed a tail about 40° long, and on the 5th it passed over the star Arcturus. Its period of revolution appears to be about 2000 years. 1861 II., June-July.—Became suddenly visible at the end of June. In the opinion of Sir John Herschel this comet surpassed in grandeur the comets of 1811 and 1858. On June 30 the nucleus was equal to the brightness of Venus, and the tail was 80° long; but early in July it increased to 90°. One observer estimated its length as 100° on July 2. This comet remained visible during twelve months. It appears to have an elliptical orbit, with a period of 409 years. 1874, July.—Coggia’s Comet: a fine object in the northern sky. On July 14 the tail was 35° long, and it remained visible several days after the nucleus had disappeared below the horizon. The nucleus was about equal to a star of the 1st mag. Orbit probably elliptical, with a period of about 5711 years. 1880 I., Jan.-Feb.—A southern comet, with a long narrow tail, variously estimated from 30° to 40° in length. It passed very near to the Sun, and presents an orbital resemblance to the fine comets of 1680 and 1843. 1881 III., June-July.—This large comet appeared in the northern heavens on June 22, and became generally visible to observers in England. On the 27th it had a tail 15° long. Its period of visibility extended over nine months. 1881 IV., Aug.—This comet is scarcely entitled to rank as one of exceptional character; but it was a conspicuous object for several weeks in August, and had a tail 6° long on the 19th.