The void in the series between Mars and Jupiter, so convinced the German astronomers of the existence of a planet to occupy it—which had hitherto escaped observation—that a systematic search for the concealed body was commenced. At Lilienthal, the residence of Schroeter, an association of twenty-four observers was formed in the year 1800, for the purpose of examining all the telescopic stars of the zodiac. The opening years of the century witnessed the anticipation substantially realized by the discovery of four planets—Ceres, Pallas, Juno, and Vesta, revolving round the sun, at a mean distance of one hundred millions of miles from Mars, so small as only to be telescopic objects. This discovery we owe to Piazzi, Olbers, and Harding. Some singular features—without parallel in the planetary system—such as their close contiguity, the intersection of their orbits, with their diminutive size—Vesta not being much larger than the Spanish peninsula—led to the surmise that these bodies are fragments of a planet, which once revolved in their mean path with a magnitude proportionate to that of its neighbors. The possibility of such a disruption cannot be denied—the revolution of the fragments round the sun would follow in obedience to the mechanical laws by which the system is governed: but the point is obviously one of those questions which must remain entirely hypothetical. Next to this addition to the system, the most remarkable astronomical occurrences of the present age are the November meteors, the renewed return of Halley’s comet, and the determination of the annual parallax of the star 61 Cygni by Bessel. These will come under consideration in future pages, with the important contributions made to science by the great names of the day, Sir John Herschel, Sir James South, Struve, Airy, Arago, and others.