80 HISTOKY OF ASTBONOMY. 



mediately rewarded with success. Two comets were dis- 

 covered in 1846, and another in 1847, the latter of which 

 became visible at noonday, when near its perihelion, 

 and for which the King of Denmark's gold medal was 

 awarded. 



The search after small planets lying between Mars and 

 Jupiter was still more successful. His plan for detecting 

 them was to observe and map all the stars down to the 

 eleventh magnitude for several degrees on each side of 

 the ecliptic, and then by a subsequent observation noting 

 whether any of them seemed to have changed its place, 

 this being the only planetary characteristic observable. 

 For the discoveries of Iris and Flora in 1847, a prize on 

 the Lalande foundation was received from the Academy 

 of Sciences at Paris in April, 1850 ; and in February, 185% 

 he received the gold medal of the Eoyal Astronomical 

 Society of London for his numerous astronomical dis- 

 coveries, and in particular for his discovery of eight small 

 planets. 



The rapid discovery of thirty-six new asteroids, after a 

 barren interval of almost forty years from the discovery 

 of Yesta, is calculated to excite surprise ; but it is ex- 

 plained by the diminutive size of the new planets, and 

 the great increase in the number of observers, as well as 

 the use of more powerful instruments. Vesta appears 

 like a star of the sixth magnitude, Pallas of the seventh, 

 while Ceres and Juno are of the eighth. Of the thirty- 

 six asteroids more recently discovered, none of them, if 

 we except perhaps Iris, Flora, and Laetitia, are larger 



