5 6 LIGHT SCIENCE FOR LEISURE HOURS. 



as an astronomer, but by the general reader. Encke 

 the man is presented to our view, as well as Encke the 

 astronomer. With loving pains the pupil of the great 

 astronomer handles the theme he has selected. The 

 boyhood of Encke, his studies, his soldier life in the 

 great uprising against Napoleon in 1813, and his work 

 at the Seeberge Observatory ; his labours on comets and 

 asteroids; his investigations of the transits of 1761 

 and 1769; his life as an academician, and as director 

 of an important observatory ; his orations at festival 

 and funeral ; and lastly, his illness and death, are de- 

 scribed in these pages by one who held Encke in 

 grateful remembrance as ( teacher and master,' and as 

 6 a fatherly friend.' 



Not 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. 



(From Nature, March 10, 1870.) 



VENUS ON THE SUN'S FACE. 



MORE than a century ago scientific men were looking 

 forward with eager interest to the passage of the 

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

 E-oyal Society judged the approaching event to be of 

 such extreme importance to the science of astronomy, 



