538 



COSMOS. 



perihelia are situated beyond the orbits of Jupiter and Saturn. 

 Of the telescopic comets, there are at the present time upon 

 an average at least 2 or 3 discovered annually. In three sue- 



in separate succession during seven equal periods, 13, 10, 2, 

 10, 4, 4, and 9. The following are the individual years : 



1500 -1550 



13 Com. 

 16001650 



3607 



1618 



2 Com. 



17001750 

 1702 

 1744 

 1784 (2) 



4 Com. 



18001850 

 1807 

 1811 

 1819 

 1823 

 1830 

 1835 

 1843 

 1845 

 1847 



15501600 



10 Com. 

 16501700 



1652 



1664 



1665 



166S 



1672 



1680 



1682 



1686 



1689 



1696 



10 Com. 

 17501800 

 1759 

 1766 

 1769 

 1781 



4 Com. 



9 Com. 



