36 EPOCHS IN THE HISTORY OP THE CONTEMPLATION OP 



Childrey (16581661) discovered the Zodiacal Light, of 

 which, however, the true relations in space were first deter- 

 mined by Dominic Cassini in 1683. Cassini regarded it 

 not as a part of the solar atmosphere, but, like Schubert, 

 Laplace, and Poisson, as a detached separately revolving 

 nebulous ring. ( 502 ) Next to the demonstration of the 

 existence of secondary planets or satellites, and of the de- 

 tached and concentrically divided ring of Saturn, the disco- 

 very of the probable existence of the nebulous ring of the 

 Zodiacal Light unquestionably constitutes one of the grand- 

 est enlargements in our view of the planetary system, which 

 at first appeared so simple. In our own days the closely 

 interwoven orbits of the small planets between Mars and 

 Jupiter, the comets of short period which remain within our 

 system (the first of which was shewn to be such by Encke), 

 and the showers of shooting stars occurring on particular 

 days (if we may regard these bodies as small cosmical 

 masses moving with planetary velocity), have enriched the 

 view of our solar system with new and wonderfully varied 

 objects of contemplation. 



In the first part of the period of which we are treating, 

 in the age of Kepler and Galileo, great additions were also 

 made to the view of the contents of space, or of the dis- 

 tribution of the material creation, beyond the outermost 

 (planetary orbit, and beyond the path of any comet. In the 

 same period (15721604) in which three new stars of the 

 first magnitude appeared in Cassiopea, Cygnus, and Ophiu- 

 chus, David Tabricius, Protestant minister of Oslell in Er.st 

 Friesland (the father of the discoverer of the solar spots), 

 in 1596, and Johann Bayer, at Augsburg, in 1608, re- 

 marked -in the neck of Cetus a star which disappeared 



