THE SMITHSONIAN INSTITUTION. 139 



Star very near the place where Olbers had asserted that the fragment^ 

 of the shattered planet must all pass. On the evening of the fourth he 

 found that the star had changed its place. This planet was named 

 Juno. Its orbit was computed by Gauss, who found its distance from 

 the sun to coincide nearly with those of Ceres and Pallas. 



Stimulated by this new discovery, Olbers continued with unwearied 

 assiduitv to explore the two regions of the heavens already referred to, 

 and, after three years of laborious search, his perseverance was crowned 

 with success. On the 29th of March, 1807, he discovered a small star 

 in a place where none had been found in his previous examinations. 

 He soon satisfied himself that this object was a planet; and it received 

 the name of Vesta. The elements of the orbit were determined by 

 Gauss, who found its distance from the sun to be a little less than that 

 of Ceres, Pallas, or Juno. 



Dr. Olbers continued his systematic examination of the heavens until 

 1816, but was rewarded by no further planetary discoveries. 



In 1825, a fresh impulse was given to researches of this nature by 

 the resolution of the Berlin Academy, to procure the construction of a 

 series of charts showing the position of all stars down to the ninth mag- 

 nitude situated within fifteen degrees of the equator. Only about two 

 thirds of the charts contemplated in this great undertaking have 3'et 

 been executed. 



After the discovery of Vesta, succeeded a long interv^al of thirty-eight 

 years, during which the excitement created by these first discoveries 

 subsided, and the search for new planets was generally abandoned. 



At length, in 1845, a fifth asteroid was announced by an observer 

 hitherto unknown to fame, Hencke, of Germany. In 1847, the same 

 observer announced a sixth asteroid, and from this time numerous ob- 

 servers in every part of Europe devoted much of their time, while some 

 devoted nearly all of their energies to the search lor planetary bodies ; 

 and discoveries at once multiplied with astonishing rapidity. Three 

 new asteroids were discovered in 1847, one in 1848, one in J 849, three 

 in 1850, two in 1851, eight in 1852, four in 1853, and six have been 

 announced during the year 1854, making at the present time a total of 

 thirty-three. Of these thirtv-three ten were first discovered by Mr. 

 Hind, of London; seven by Dr. Gasparis, of Naples; three by Luther, 

 of Bilk ; while Dr. Olbers, of Bremen, Hencke, of Driesen, Chacornac, 

 of Paris, and Goldsmith, also of Paris, have each of them discovered 

 two asteroids; and Piazzi, Harding, Graham, Marth, and finally Fer- 

 guson, of our own National Observatory, have each discovered one. 

 Moreover, in several instances, the same planet has been independently 

 discovered by more than one astronomer. 



In scarcely a single instance could these discoveries be termed the 

 result of accident. They have been the result of a laborious search 

 expressly undertaken for the discovery of these bodies. Mr. Hind, who 

 has been the most successful explorer in this field, nearly ten years ago 

 commenced comparing the Berlin charts with the heavens, and began 

 to map down for himself the stars in other regions of the ecliptic, which 

 did not fall within the limits of the Berlin charts. Any discrepancj- 

 I between the stars on the maps and the stars in the heavens was care- 

 fully scrutinized ; so that if a new star presumed to show itself within 



