92 HISTORY OF ASTKONOMY. 



and not a solitary one in any other portion of the solar 

 system, points to something special in this region of the 

 heavens. In other words, we have discovered a limited 

 zone of little planetary bodies, and have not been able 

 to discover a single body of the same class situated out 

 of this zone. 



3. The orbits of these little bodies present some special 

 peculiarities. 



If we refer to the table on page 83, we shall perceive 

 that the perihelia of the orbits are not distributed uni- 

 formly through the zodiac. In the first quarter of the 

 zodiac we find seventeen perihelia, in the second quarter 

 twelve, in the third quarter six, and in the fourth quarter 

 five. The ascending nodes of the orbits are distributed 

 with greater uniformity. Thus, in the first quadrant 

 we find twelve nodes, in the second thirteen, in the third 

 eight, and in the fourth seven. 



The greatest inclination in the case of any of the larger 

 planets is seven degrees ; but the inclinations of the 

 orbits of the asteroids range from near zero to thirty- 

 five degrees, the inclination of seventeen of the orbits 

 exceeding seven degrees. The greatest eccentricity in the 

 case of any of the large planets is one fifth ; but the 

 eccentricities of the orbits of the asteroids range from 

 near zero to one third. 



4. But the most striking peculiarity of these orbits is, 

 that they all lock into one another like the links of a 

 chain, so that if the orbits are supposed to be represented 

 materially as hoops, they all hang together as one system. 



