236 THE ASTEROIDS. 



mere accidental coincidence, and to confirm them in the belief that there 

 must.be a missing jDlanet outside of Mars. The impression was so strong 

 that an organization of twenty-four astronomers was formed by the exer- 

 tions of Baron Zach, to search for it. Curiously enough, however, the good 

 fortune of discovery did not fall to any one of their number, but to Piazzi, 

 the Sicilian astronomer, who on the opening night of the century, in the 

 course of observations for his famous star-catalogue, came upon a star of 

 the seventh magnitude in a place where a short time before he was sure no 

 such object existed. In a single day its motion was suffioient to prove its 

 planetary character, and lie continued to observe it, though much hindered 

 by ill health and unfavorable weather, until it was lost in the rays of the 

 sun. He was the only observer, however, for in those days communication 

 was so slow that the planet had disaj^peared before the Continental as- 

 tronomers could be notified of the discovery; and to find it again was hardly 

 less difiicult than at first. Gauss, then just beginning his career, came to 

 the rescue with a new and entirel}^ original method, by which from Piazzi's 

 six weeks of observation he deduced the planet's orbit and computed an 

 ephemeris by means of which Zach- rediscovered it on December 31st, and 

 Olbers independently on January 1st. 



In searching for Ceres, Olbers had noted carefully the configuration of 

 telescopic stars in that part of the sky where he expected to find her, and 

 on reexamining the region a few weeks later he was so fortunate onMarch 

 28th, 1802, as to discover another planet, Pallas. The existence of two of 

 these little bodies suggested the hypothesis that they originated in the 

 breaking up of a much larger body, of which probably numerous fragments 

 must exist which might be found by careful search near the points where 

 the orbits of Ceres and Pallas intersect. A search was instituted, and in 

 1804 Juno was discovered by Harding, and in 1807 Vesta, the only one ever 

 visible with the naked eye, by Olbers. The hunt was kept up until 1816 

 but without result, as the observations did not include stars sufficiently 

 faint. 



About 1830 Hencke, postmaster of the little village of Driessen, took up 

 the subject, and after fifteen years of patient searching was rewarded by 

 the discovery of Astraja in December, 1845. The year 1846 was sufficiently 

 signalized by the discovery of Neptune; but since then not a year has 

 passed without adding to the roll of the Asteroids. In 1861 and 1876 each, 

 10 wei-e discovered; in 1872, 11; in 1868, 12; and in 1875, 17. 



The list of discoverers includes thirty-one different names: Fourteen of 

 them stand credited with a single planet each, and ten with five or more 

 apiece. Dr. Peters, of Clinton, New York, heads the list with twenty-six; 

 Luther, of Dtisseldorff, comes next with twenty; then follows Watson, of 

 Ann Arbor, with nineteen, and Goldschmidt, of Paris, with fourteen. Fifty- 

 two of these planets were discovered in France, fifty- four by American ob- 

 servers, thirty-nine by Germans, nineteen in England and its dependencies, 

 and eleven in Italy and Sicily. 



