PORTION OF THE COSMOS. THE SOLAR DOMAIN. 265 



Earth, 4 to Jupiter, 8 to Saturn, 6 to Uranus, 2 to 

 Neptune) . 



One hundred and ninety-seven Comets, whose paths 

 have been calculated : amongst them are 6 interior, i. e. 

 whose aphelia are included within the outermost planetary 

 orbit, viz. that of Neptune. 



The solar system comprises, besides the above-mentioned 

 bodies, with great probability, the ring of the Zodiacal 

 Liglit } situated perhaps between the orbits of Yenus and 

 Mars. 



And, according to the opinion of many observers, the 

 host of meteoric asteroids which intersect the Earth's 

 path, more especially at particular points. 



In the above enumeration of the 22 planets, of which 6 

 were known previous to the 13th of March 1781, the 8 

 greater planets are distinguished by larger type from the 

 14 smaller planets, sometimes called " co-planets," or 

 " asteroids," whose intersecting orbits are situated between 

 Mars and Jupiter. 



In the modern history of planetary discoveries, the leading 

 epochs have been the discovery by William Herschel at 

 Bath on the 13th of March, 1781, of Uranus, being the 

 first planet discovered beyond the orbit of Saturn, and 

 recognised as a planet by its disk and by its motion ; the 

 discovery by Piazzi, at Palermo, on the 1st of January, 1801, 

 of Ceres, the first of the smaller planets ; the recognition 

 by Encke, at Gotha, in August 1819, of the first " interior" 

 comet ; and the announcement from calculations of plane- 

 tary disturbances of the existence of Neptune by Le Yerrier, 

 at Paris, in August 1846, as well as its actual discovery by 

 Galle, at Berlin, on the 23d of September of the same year. 



