302 SPECIAL RESULTS IN THE URANOLOGICAL 



their discovery, we find that nine were first seen in the 17th 

 century, nine again in the 18th, and eighteen in the first 

 half of the present or 19th century. 



Chronological table of planetary discoveries, or of pri- 

 mary planets and satellites, since the invention of the 

 telescope, in 1608 ; 



A. The Seventeenth Century. 



Four satellites of Jupiter : by Simon Marius, at Ansbach, 

 Dec. 29, 1609; and by Galileo, at Padua, Jan. 7, 1610. 



Compound form of Saturn: Galileo, Nov. 1610; the 

 two side anses seen by Hevelius, 1656 ; final recognition of 

 the true form of the ring by Huygens, Dec. 17, 1657. 



The 6th satellite o^Saturn (Titan) : Huygens, March 25, 

 1655. 



The 8th satellite of Saturn (the outermost one, Japetus) : 

 Domin. Cassini, Oct. 1671. 



The 5th satellite of Saturn (Ehea) : Cassini, Dec. 23, 

 1672. 



The 3d and 4th satellites of Saturn (Tethys and Dione) : 

 Cassini, end of March 1684. 



B. Eighteenth Century. 



URANUS : William Herschel, March 13, 1781, at Bath. 



The 2d and 4th satellites of Uranus : William Herschel, 

 Jan. 11, 1787. 



The 1st satellite of Saturn (Mimas) : W. Herschel, Aug. 

 28, 1789. 



The 2d satellite of Saturn (Enceladus) : W. Herschel, 

 Sept. 17, 1789. 



The 1st satellite of Uranus : W. Herschel, Jan. 18 

 1790. 



