66 LIGHT SCIENCE FOR LEISURE HOURS. 



labors on comets and asteroids ; his investigations of 

 the transits of 1T61 and 1769 ; his life as an acade- 

 mician, and as director of an important observatory ; 

 his orations at festival and funeral ; and lastly, his 

 illness and death, are described in these pages by one 

 who held Encke in grateful remembrance as " teacher 

 and master," and as " a fatherly friend." 



Xot the least interesting feature of the work is the 

 correspondence introduced into its pages. We find 

 Encke in communication with Humboldt, with Bessel 

 and Struve, with Hansen, Olbers, and Argelander; 

 with a host, in fine, of living as well as of departed 

 men of science. 



CFrom Nature, March 10, 1870.) 



VENUS ON THE SUN'S FACE. 



MOKE than a century ago scientific men were look- 

 ing forward with eager interest to the passage of the 

 planet Yenus across the sun's face in 1769. The 

 Royal Society judged the approaching event to be of 

 such extreme importance to the science of astronomy, 

 that they presented a memorial to King George III., 

 requesting that a vessel might be fitted out, at govern- 

 ment expense, to convey skilful observers to one of the 

 stations which had been judged suitable for observing 

 the phenomenon. The petition was complied with, 



